Organic light active devices with particulated light active material in a carrier matrix

ABSTRACT

A light active device includes a semiconductor particulate dispersed within a carrier material. A first contact layer is provided so that on application of an electric field charge carriers having a polarity are injected into the semiconductor particulate through the conductive carrier material. A second contact layer is provided so that on application of the electric field to the second contact layer charge carriers having an opposite polarity are injected into the semiconductor particulate through the conductive carrier material. The semiconductor particulate comprises at least one of an organic and an inorganic semiconductor. The semiconductor particulate may comprise an organic light active particulate that includes at least one conjugated polymer. When an electric field is applied between the first and second contact layers to the semiconductor particulate through the conductive carrier material, the second contact layer becomes positive relative to the first contact layer and charge carriers of opposite polarity are injected into the semiconductor particulate. The opposite polarity charge carriers combine to form in the conjugated polymer charge carrier pairs which decay radiatively so that radiation is emitted from the conjugated polymer. In this case, the inventive light active device acts as a light emitting diode.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part of U.S. Utility patent application Ser.No. 10/321,161, filed Dec. 17, 2002 which is the U.S. Utility patentapplication of a Provisional Patent Application Ser. No. 60/427,333,filed Nov. 19, 2002.

BACKGROUND OF THE INVENTION

The present invention pertains to organic light active devices. Moreparticularly, the present invention pertains to devices and methods forfabricating organic light active devices that can be used forapplications such as general lighting, display backlighting, videodisplays, Internet appliances, electronic books, maps, digitalnewspapers, stereoscopic vision aides, head mounted displays, advancedvehicle windshields, solar cells, cameras and photodetectors. Amulti-color single layer light active device is disclosed. Alsodisclosed is a sequential burst driving scheme for a multi-color singlelayer display. Further disclosed are methods for making organic lightactive material particulate, as well as an organic light active fiber.

A polymer is made up of organic molecules bonded together. For a polymerto be electrically conductive it must act like a metal with theelectrons in the bonds mobile and not bound to the atoms making up theorganic molecules. A conductive polymer must have alternate single anddouble bonds, termed conjugated double bonds. Polyacetylene is a simpleconjugated polymer. It is made by the polymerization of acetylene. Inthe early 1970's, a researcher named Shirakawa was studying thepolymerization of acetylene. When too much catalyst was added, themixture seemed to have a metallic appearance. But unlike metals theresulting polyacetylene film was not an electrical conductor. In themid-1970's the film was reacted with iodine vapor. The result was anextreme increase in the conductivity of the polymer film, and ultimatelyresulted in a Nobel Prize in Chemistry for the researchers whodiscovered it.

Although polyacetylene can be made as conductive as some metals, itsconductivity drops rapidly in contact with air. This has led to thedevelopment of more stable, conjugated polymers, for example,polypyrrol, polyaniline and polytiophene.

There is now intensive development working with conjugated polymers intheir un-doped, semiconductive state. It was found that some conjugatedpolymers exhibit electroluminescence when a voltage is applied. Further,the absorption of light by the semiconductive polymer results inpositive and negative charges that produce an electric current. Thus,conjugated polymers can be used to make solar cells and light detectors.

Organic light active material (“OLAM™”) makes use of the relativelyrecent discovery that polymers can be made to be conductors. Organiclight emitting diodes (“OLED”) convert electrical energy into light,behaving as a forward biased pn junction. OLAMs can be light emitters orlight detectors, depending on the material composition and the devicestructure. For the purpose of this disclosure, the term OLAM and OLEDcan be interchanged. In its basic form, an OLED is comprised of a layerof hole transport material upon which is formed a layer of electrontransport material. The interface between these layers forms aheterojunction. These layers are disposed between two electrodes, withthe hole transport layer being adjacent to an anode electrode and theelectron transport layer being adjacent to a cathode electrode. Uponapplication of a voltage to the electrodes, electrons and holes areinjected from the cathode electrode and the anode electrode. Theelectron and hole carriers recombine at the heterojunction formingexcitons and emitting light.

The basic structure of an OLED display is similar to a conventional LCD,where the reactive material (in the LCD case, a liquid crystal, in theOLED case, a conjugated polymer) is sandwiched between electrodes. Whenan electric field is applied by the electrodes, the OLED material isbrought into an excited energy state, this energy state drops down bythe emission of photons, packets of light. Thus, each pixel of the OLEDdisplay can be controlled to emit light as needed to create a displayedimage.

Besides attractive picture quality, an OLED display device consumes lesspower than liquid crystal display technologies because it emits its ownlight and does not need backlighting. OLED displays are thin,lightweight, and may be able to be manufactured on flexible materialssuch as plastic.

Unlike liquid-crystal displays, OLEDs emit light that can be viewed fromany angle, similar to a television screen. As compared to LCDs, OLEDsare expected to be much less expensive to manufacture, use less power tooperate, emit brighter and sharper images, and “switch” images faster,meaning that videos or animation run more smoothly.

Recently, an effort has been made to create equipment and provideservices for manufacturing OLED screens. The potential OLED displaymarket includes a wide range of electronic products such as mobilephones, personal digital assistants, digital cameras, camcorders,micro-displays, personal computers, Internet appliances and otherconsumer products.

There is still a need, for example, for a thin, lightweight, flexible,bright, wireless display. Such a device would be self-powered, robust,include a built-in user-input mechanism, and ideally functional as amultipurpose display device for Internet, entertainment, computer, andcommunication use. The discovery of the OLED phenomenon puts this goalwithin sight.

However, there are still some technical hurdles that remain to be solvedbefore OLED displays will realize their commercial potential. OLED'slight emitting materials do not have a long service life. Presently,optimum performance in commercially viable volume production isachievable only for small screens, around 3.5 inches square or less.Storage lifetimes of at least 5 years are typically required by mostconsumer and business products, and operating lifetimes of >20,000 hoursare relevant for most applications.

Organic-light-emitting-diode technology offers the prospect of flexibledisplays on plastic substrates and roll-to-roll manufacturing processes.One of the biggest challenges to the OLED display industry is fromcontamination by water and oxygen. The materials involved in smallmolecule and polymer OLEDs are vulnerable to contamination by oxygen andwater vapor, which can trigger early failure. U.S. Pat. No. 5,247,190issued to Friend et al., teaches an electroluminescent device comprisinga semiconductor layer in the form of a thin dense polymer filmcomprising at least one conjugated polymer sandwiched between twocontact layers that inject holes and electrons into the thin polymerfilm. The injected holes and electrons result in the emission of lightfrom the thin polymer film.

Recently, there has been activity in developing thin, flexible displaysthat utilize pixels of electro-luminescent materials, such as OLEDs.Such displays do not require any back lighting since each pixel elementgenerates its own light. Typically, the organic materials are depositedby solution processing such as spin-coating, by vacuum deposition orevaporation. As examples, U.S. Pat. No. 6,395,328, issued to May,teaches an organic light emitting color display wherein a multi-colordevice is formed by depositing and patterning thin layers of lightemissive material. U.S. Pat. No. 5,965,979, issued to Friend, et al.,teaches a method of making a light emitting device by laminating twoself-supporting components, at least one of which has a thin layer oflight emitting layer. U.S. Pat. No. 6,087,196, issued to Strum, et al.,teaches a fabrication method for forming organic semiconductor devicesusing ink jet printing for forming thin layers of organic light emittingmaterial. U.S. Pat. No. 6,416,885 B1, issued to Towns et al., teaches anelectro-luminescent device wherein a conductive polymer thin layer isdisposed between an organic light emitting thin layer and acharge-injecting thin layer that resists lateral spreading of chargecarriers to improve the display characteristics. U.S. Pat. No. 6,48,200B1, issued to Yamazaki et al., teaches a method of manufacturing anelectro-optical device using a relief printing or screen printing methodfor printing thin layers of electro-optical material. U.S. Pat. No.6,402,579 B1, issued to Pichler et al., teaches an organiclight-emitting device in which a multi-layer structure is formed by DCmagnetron sputtering to form multiple thin layers of organic lightemitting material. U.S. Pat. No. 6,50,687 B1, issued to Jacobson,teaches an electronically addressable micro-encapsulated ink anddisplay. In accordance with the teachings of this reference,microcapsules are formed with a reflective side and a light absorbingside. The microcapsules act as pixels that can be flipped between thetwo states, and then keep that state without any additional power. Inaccordance with the teaching of this reference, a reflective display isproduced where the pixels reflect or absorb ambient light depending onthe orientation of the microcapsules. U.S. Pat. No. 5,858,561, issued toEpstein et al., teaches a light emitting bipolar device consisting of athin layer of organic light emitting material sandwiched two layers ofinsulating material. The device can be operated with AC voltage or DCvoltage. U.S. Pat. No. 6,433,355 B1, issued to Riess et al., teaches anorganic light emitting device wherein a thin organic film region isdisposed between an anode electrode and a cathode electrode, at leastone of the electrodes comprises a non-degenerate wide band-gapsemiconductor to improve the operating characteristic of the lightemitting device. U.S. Pat. No. 6,445,126 B1, issued to Arai et al.,teaches an organic light emitting device wherein an organic thin layeris disposed between electrodes. An inorganic electrode or hole injectingthin film is provided to improve efficiency, extend effective life andlower the cost of the light emitting device.

It is known to form a thin OLED layer by various method including vacuumdeposition, evaporation or spin coating. Thin layers of hole transportmaterial and then electron transport material are formed by these knownmethods over a grid of anode electrodes. The anode electrodes are formedon a glass plate. A grid of cathode electrodes is then placed adjacentto the electron transport material supported by a second glass plate.Thus, the basic OLED organic stack is sandwiched between electrodes andglass plate substrates. It is generally very difficult to form theelectrodes with the precise alignment needed for forming a pixilateddisplay. This task is made even more difficult in a multicolor display,where the OLED pixels emitting, for example, red, green and blue, areformed side-by-side to fabricate a full color display. Because the OLEDmaterial and electrodes can be made transparent, it is possible to stackthe color OLED pixels on top of each other, allowing for a higher pixelpacking density and thus the potential for a higher resolution display.However, the electrode alignment issue still poses a problem. Typically,the well-known use of shadow masks are employed to fabricate the pixelcomponents. Aligning the shadow masks is difficult, and requires extremeprecision.

Currently, inkjet printing has gained ground as a promising fabricationmethod for making OLED displays. The core of this technology is verymature, and can be found in millions of computer printers around theworld. However, there are some serious disadvantages to the adapting ofinkjet printing to OLED display fabrication. It is still difficult tolay down precise layers of material using the spray heads of inkjetprinters. Inkjet printing does not adequately overcome the problem ofmaterial degradation by oxygen and water vapor. Elaborate and expensivematerials and fabrication processes are needed to provide adequateencapsulation of the display elements to prevent early degradation ofthe OLED material due to water and oxygen ingress. As an attempt tosolve this contamination problem, Vitex Systems, Sunnyvale, Calif., hasdeveloped a barrier material in which a monomer vapor is deposited on apolymer substrate, and then the monomer is polymerized. A thin layer ofaluminum oxide a few hundred angstroms thick is deposited on thepolymerized surface. This process is repeated a number of times to forman encapsulation barrier over an OLED display. This elaborateencapsulation barrier is an example of the effort taken to prevent waterand oxygen from contaminating the easily degraded OLED films that form aconventional OLED display device. Even with this elaborate encapsulationprocess, the edges of the OLED display still need to be sealed.

It is difficult to align display pixel-sized electrodes and inkjetprinted OLED material with the accuracy needed to effect a highresolution display. Due to the very thin layers of material involved informing conventional OLED devices, shorts and the destruction of pixelsresult from the inclusion of miniscule foreign particles, requiring theuse of expensive clean room or vacuum manufacturing facility for thevarious prior art fabrication methods. Accordingly there is a need foran improved fabrication method for forming OLED devices.

There is also a need for a multi-color OLED structure whereby two ormore colors of light can be produced from a single pixel or OLED device.U.S. Pat. No. 6,117,567, issued to Andersson et al, teaches a lightemitting polymer device for obtaining voltage controlled colors based ona thin polymer film incorporating more than one electroluminescentconjugated polymer. The polymer thin film is sandwiched between twoelectrodes. Upon application of different voltages to the electrodes,different colors of light are emitted from the conjugated polymerscontained in the thin film.

Edwin Land introduced a theory of color vision based on center/surroundretinex (see, An Alternative Technique for the Computation of theDesignator in the Retinex Theory of Color Vision,” Proceedings of theNational Academy of Science, Volume 83, pp. 3078-3080, 1986). Landdisclosed his retinex theory in “Color Vision and The Natural Image,”Proceedings of the National Academy of Science, Volume 45, pp. 115-129,1959. These retinex concepts are models for human color perception.Others have shown that a digital image can be improved utilizing thephenomenon of retinex (see, U.S. Pat. No. 5,991,456 issued to Rahman etal, the disclosure of which is incorporated by reference herein). Theinventors of the U.S. Pat. No. 5,991,456 patent used Land's retinextheory and devised a method of improving a digital image where the imageis initially represented by digital data indexed to represent positionson a display. According to the inventors of the U.S. Pat. No. 5,991,456patent, an improved digital image can then be displayed based on theadjusted intensity value for each i-th spectral band so-filtered foreach position. For color images, a novel color restoration step is addedto give the image true-to-life color that closely matches humanobservation.

Nanoparticles are used in unrelated applications, such as drug deliverdevices. Others have shown that very small polymer-based particles canbe made by a variety of methods. These nanoparticles vary in size from10 to 1000 nm. A drug can be dissolved, entrapped, encapsulated orattached to a nanoparticle matrix. Depending on the method ofpreparation, nanparticles, nanospheres or nanocapsules can be obtianed.(see, Biodegradable Polymeric Nanoparticles as Drug Delivery Devices, K.S., Soppimath et al., Journal of Controlled Release, 70(2001) 1-20).

The current state of the OLED fabrication technology requires theformation of very thin films of organic light emitting material. Thesethin films are formed by known techniques such as vacuum deposition,screen printing, transfer printing and spin coating, or by there-purposing of existing technology such as ink jet printing. In anycase, the current state of the art has at its core the formation of verythin film layers of organic material. These thin films must also bedeposited very uniformly and precisely, which has proven extremelydifficult to do. These thin layers of organic material are susceptibleto major problems, such as delamination, particularly when applied to aflexible substrate. The extreme thinness of the layers of organicmaterial between conductors also results in electrical shorts easilyforming due to even very small specks of dust or other contaminants.Because of this limitation, costly cleanroom facilities must be builtand maintained using the conventional OLED thin film fabricationtechniques. Organic light emitting devices offer tremendous potentialdue to the nature of the raw materials, however, the current state ofthe art fabrication methods are limiting the delivery of this potentialto the consumer.

SUMMARY OF THE INVENTION

It is an object of the present invention to overcome the drawbacks ofthe prior art. It is an object of the present invention to provide amethod of fabricating a light active device by dispersing threedimensionally a semiconductor particulate within a carrier material. Theresulting structure has individual point sources of light emissiondispersed with a protective barrier material. The barrier materialprovides strength to the device and adhesion to the electrodes and/orother films and prevents contamination of the semiconductor particulate.The inventive fabrication method also allows multiple colors to beemitted from the inventive mixture between a single pair of electrodesforming a pixel or device. In an inventive display driving scheme, anarray of such pixels is driven so that bursts of color emissions occursin rapid succession resulting in the perception by the human eye of arange of colors in the visible spectrum. Thus, in accordance with thisaspect of the invention, a single emissive layer and pair of electrodescan be used to create a full color video display. The inventive OLAM™structure can also be used to detect a spectrum of colors when thedevice is constructed as a photodetector.

In accordance with an aspect of the present invention, a light activedevice includes a semiconductor particulate dispersed within a carriermaterial. A first contact layer is provided so that on application of anelectric field charge carriers having a polarity are injected into thesemiconductor particulate through the conductive carrier material. Asecond contact layer is provided so that on application of the electricfield to the second contact layer charge carriers having an oppositepolarity are injected into the semiconductor particulate through theconductive carrier material. The semiconductor particulate comprises atleast one of an organic and an inorganic semiconductor. Thesemiconductor particulate may comprise an organic light activeparticulate that includes at least one conjugated polymer. When anelectric field is applied between the first and second contact layers tothe semiconductor particulate through the conductive carrier material,the second contact layer becomes positive relative to the first contactlayer and charge carriers of opposite polarity are injected into thesemiconductor particulate. The opposite polarity charge carriers combineto form in the conjugated polymer charge carrier pairs which decayradiatively so that radiation is emitted from the conjugated polymer. Inthis case, the inventive light active device acts as a light emittingdiode.

Importantly, the present invention can be used with small molecule OLEDmaterials as well as large molecule OLED materials. It is very difficultor impossible to dissolve small molecule OLED materials in a liquid andso the current state-of-the-art requires the material to be deposited asa very thin film to form an OLED device, using for example, a processsimilar to the fabrication of computer microprocessor chip. But becausethe displays are typically much larger than chips, that fabricationprocess is prohibitively expensive for forming a large display. However,in accordance with the present invention, particulate of the smallmolecule OLED material can be mixed with the carrier material anddisposed within the gap between the electrodes. The particulate caninclude other materials, such as organic and inorganic characteristicenhancing materials to control the electrical, chemical, optical,mechanical and magnetic properties of the light active device.

The organic light active particulate may includes particles comprisedfrom a polymer blend. The polymer blend including at least one organicemitter blended with at least one of a hole transport material, ablocking material, and an electron transport material. The organic lightactive particulate may include microcapsules having a polymer shellencapsulating an internal phase. The internal phase and/or the shell canbe comprised of a polymer blend including an organic emitter blendedwith at least one of a hole transport material, a blocking material, andan electron transport material.

To form a display device, the first contact layer and the second contactlayer can be arranged to form an array of pixel electrodes. Each pixelincludes a portion of the semiconductor particulate dispersed within theconductive carrier material. Each pixel is selectively addressable byapplying a driving voltage to the appropriate first contact electrodeand the second contact electrode.

Another aspect of the present invention provides a voltage controlledlight active device for emitting two or more colors of light. A firstelectrode and a second electrode are disposed adjacent to each otherwith a gap between them. A mixture of an organic light activeparticulate and a conductive carrier material is disposed within thegap. Because of the particulate/carrier mixture, the gap between theelectrodes (or what ever layers are sandwiching the organic emissivelayer) can be wider than the thickness of the emissive particulate. Theparticulate is dispersed three dimensionally throughout a conductivecarrier. By this construction, many of the drawbacks, such as electricalshorts, delamination, etc., that plauge the very thin polymer filmfabrication methods are overcome. The organic light active particulateis comprised of first emitting particles including a firstelectroluminescent conjugated polymer. The first emitting particles emita number of photons of a first color in response to a first turn-onvoltage applied to the electrodes. The first emitting particles alsoemit a different number of photons, zero or more, of the first color inresponse to other turn-on voltages. The organic light active particulatefurther comprises second emitting particles including a secondconjugated polymer. The second emitting particles emit a number ofphotons of a second color in response to a second turn-on voltage and adifferent number of photons of the second color in response to otherturn-on voltages. Thus, in the case of a multi-colored diode or display,different colors are perceivable by the human eye depending on theapplied turn-on voltage.

The organic light active layer may also include third emitting particlesincluding a third electroluminescent conjugated polymer. The thirdemitting particles emit a number of photons of a third color and/orintensity in response to a third turn-on voltage applied to theelectrodes and a different number of photons of the third color and/orintensity in response to other turn-on voltages. A full color displaycan be obtained by incorporating an array of pixels each capable ofemitting different colors, such as a first color red, a second colorgreen and a third color blue. The color emitters can be a mix of organicand inorganic materials. For example, an organic conjugated polymeremitter can be used as a red emitter and an inorganic rare earth metalor metal alloy, or doped inorganic semiconductor, can be used as a greenemitter. This combination of organic and inorganic emitters may expandthe potential candidates for emissive materials enabling the inventivedevice to be tuned for specific applications.

The voltage controlled organic light active device can be constructed asa display. In this case, the first electrode is part of an x-grid ofelectrodes and the second electrode is part of a y-grid of electrodes.The mixture of the organic light active particulate and the conductivecarrier material in the gap between the first electrode and the secondelectrode make up an emissive component of a pixel of a display device.Depending on the device structure it can be driven as a passive matrixor an active matrix device.

In accordance with the present invention, an organic light activedisplay device includes a substrate with a first grid of drivingelectrodes formed on the substrate. A second grid of electrodes isdisposed adjacent to the first grid of electrodes and defines a gaptherebetween. A mixture of an organic light active particulate and aconductive carrier material is disposed within the gap. The organiclight active particulate includes first particles including a firstelectroluminescent conjugated polymer having a first turn-on voltage andsecond particles including a second electroluminescent conjugatedpolymer having a second turn-on voltage different than the first turn-onvoltage. When the first turn-on voltage is applied, a first color isemitted by the first electroluminescent conjugated polymer. Light havinga second color is emitted by the second electroluminescent conjugatedpolymer in response to the second turn-on voltage applied to the firstelectrode and the second electrode. Additional color emitters can beincluded, including emitters that emit photons predominately in thevisible and/or non-visible range of the photon radiation spectrum. Also,the color emitters can be comprised of other organic or inorganicmaterials.

In accordance with the present invention, a method is provided fordriving a multi-color light emitting device, the multi-color lightemitting device is capable of emitting two or more colors in sequence.Each color is emitted in response to a respective different appliedturn-on voltage. During an emission cycle, a first turn-on voltage isapplied having a duration to the light emitting device so that a firstburst of a predominant number of photons of a first color are emitted. Asecond turn-on voltage is then applied during the emission cycle havinga duration and at least one of a magnitude and a polarity different thana magnitude and polarity of the first turn-on voltage. For example, a 5volt turn-on voltage may cause a predominate emission of red photons,and a 10 volt turn-on voltage may cause a predominate emission of greenphotons. In response to the second turn-on voltage duration, a secondburst of a predominant number of photons of a second color are emitted.In this way, during the emission cycle the first burst and the secondburst occur in rapid succession. A human eye and vision system receivingthe first burst and the second burst is stimulated to perceive a colorthat is different than the first color and the second color.

In accordance with another aspect of the present invention, a method isprovided for forming a layered organic light active materialparticulate. This layered organic light active material particulate ismixed with the conductive carrier material and disposed between theelectrodes to form the inventive light emitting devices. To form theparticulate, a first mixture is formed of a first organic light activecomponent material and a first carrier fluid. A second mixture is formedof a second organic light active component material and a second carrierfluid. A first mist is generated of the first mixture in an environmentso that a first particulate of the first organic light active componentmaterial is temporarily suspended in the environment. A second mist ofthe second mixture is generated in the environment so that a secondparticulate of the second organic light active component material istemporarily suspended in the environment. The first particulate and thesecond particulate are allowed to commingle and attract together in theenvironment to form a first layered organic light active materialparticulate. A charge of opposite polarity can be applied to theconstituents in each mist to promote electrical attraction. When thecharged particles join together an electrically neutral organic lightactive particulate is obtained. The layered organic light activeparticulate has a first layer made up of the first organic light activecomponent material and a second layer made up of the second organiclight active component material. Additional layers can be added to themultilayered structure by forming another mixture of another organiclight active component material and another carrier fluid and formingyet another mixture of a previously formed layered organic light activematerial particulate and yet another carrier fluid. The resultingparticles are suspended in the environment as described above andallowed to commingle and attract together to form the multilayeredparticulate structure. This method can be repeated to build upmultilayered organic light active material particulate having a range ofselectable electrical, optical, mechanical and chemical attributes.Further, depending on the desired particulate characteristics, theconstituents of the multilayered structure may be organic and/orinorganic materials. The use of organic and inorganic materials broadensthe potential candidates of materials that can be combined to form themultilayered particulate. Further, the inventive method may be appliedfor making multilayered particles for other applications, such as drugdelivery vehicles, electrical circuit components, bi-polarelectropheretic microdevices, etc.

The environment in which the particulate is formed can be an inert gas,reactive gas, a vacuum, a liquid or other suitable medium. For example,it may advantageous for the environment to include elements that performa catalytic function to promote a chemical reaction in or between theconstituents in the mists. A characteristic enhancing treatment may beperformed on the formed layered organic light active materialparticulate. The treatment may be a temperature treatment, a chemicaltreatment, a light energy treatment to cause, for example, lightactivated cross-linking, or other characteristic enhancing treatment toimpart desired attributes to the formed particulate.

In accordance with the present invention, an OLED device includes afirst electrode and a second electrode. The second electrode is disposedadjacent to the first electrode so that a gap is defined between them.Unlike the prior art, in accordance with the present invention, thinfilms of OLED material are not required to be formed. Instead, thepresent invention utilizes OLED particulate dispersed within aconductive carrier. The OLED particulate is dispersed within the carriermaterial, which is disposed within the gap between the electrodes. Whenan electric potential is applied to the electrodes, the electricalenergy passes through the carrier material raising the energy state ofthe OLED particulate, resulting in the emission of light.

In a simple form, the OLED particulate may comprise organic-layeredparticles, each particle including a hole transport layer and anelectron emitter layer. A heterojunction is formed at the interfacebetween the hole transport layer and the electron emitter layer. Eachorganic-layered particle may also include a blocking layer adjacent tothe electron emitter layer and an emissive layer adjacent to the holetransport layer, thereby forming a stacked organic layered structure.The blocking layer is provided for facilitating the injection ofelectrons and holes, and the emissive layer is provided for facilitatingthe emission of photons when the energy state of the OLED particulate israised.

In accordance with an aspect of the present invention, the OLEDparticulate comprises microcapsules. Each microcapsule includes aninternal phase and a shell. The internal phase and/or the shell includethe OLED material. The internal phase and/or the shell may also includea field reactive material. Depending on the OLED fabrication method andthe desire OLED characteristics, the field reactive material may be anelectrostatic material and/or a magnetically reactive material.

As is described further herein, the microcapsule composition may beeffective for enabling a “self healing” capability of the fabricatedOLED device. In this case, the microcapsule includes a composition thatcauses the microcapsule to rupture if electrical energy above athreshold is applied to the microcapsule. For example, if a particularmicrocapsule is aligned so the during use of the OLED device it becomesa short between the electrodes, or if the microcapsule is adjacent to adust particle or other foreign inclusion, creating such a short, when aelectric potential is applied between the electrodes energy exceeding apredetermined threshold will pass through the microcapsule causing thecapsule to rupture and disconnect the short. By this construction, themicrocapsule is automatically removed from the path of conduction ofelectrical energy in the event of a short.

In accordance with another aspect of the invention, the microcapsuleshell and/or internal phase may include a composition effective toprovide a barrier against degradation of the OLED material. The OLEDmicrocapsules are dispersed within a carrier fluid. This carrier fluidalso provides a barrier against the intrusion of substances whichdegrade the OLED material.

The OLED microcapsules can have constituent parts including at least oneof hole transport material, electron transport material, field reactivematerial, solvent material, color material, shell forming material,barrier material, desiccant material, and heat meltable material. Theconstituent parts form at least one internal phase and at least oneshell. The constituent parts are selected so as to have electricalcharacteristics that result in a preferred path of electrical conductionthrough the hole transport material and the electron transport material.By this construction, the microcapsule behaves as a pn junction uponapplication of an electrical potential to the first electrode and thesecond electrode.

The OLED device can be constructed of suitably chosen materials so thatthe carrier material is relatively less electrically conductive than theOLED particulate, this ensures that the OLED particulate offers a pathof less electrical resistance than the carrier material. Thus, theelectric potential applied to the electrodes will pass through thecarrier material, which has some electrical conductivity, and throughthe OLED particulate, which has relatively higher electricalconductivity. In this way, the preferred path of electrical conductionis through the OLED particulate. Likewise, the shell of the OLEDmicrocapsules is relatively less electrically conductive than the OLEDmaterial itself, so that the OLED material offers a path of lesselectrical resistance than the shell.

The typical OLED includes an OLED component that is a hole transportmaterial and an OLED component that is an electron transport material.In accordance with a formulation of the inventive microcapsules, theshell comprises an OLED component material that is either the holetransport material or the electron transport material, and the internalphase of the microcapsule includes the OLED component material that isthe other of the hole transport material and the electron transportmaterial. Depending on the desired optical qualities of the fabricatedOLED device, the carrier material can be selected so that it has opticalproperties during use of the OLED device that are transparent,diffusive, absorptive, and/or reflective to light energy. Thecomposition of the OLED particulate can be selected so that theelectrical characteristics of the OLED particulate includes, an electroor magneto rheological characteristic. This rheological characteristicis effective for causing the OLED particulate to move within the carrierand orient in response to an applied electrical or magnetic field.

In accordance with another composition of the OLED microcapsule, theinternal phase comprises OLED material and a magnetically reactivematerial disposed within a first shell. An electrolyte and a curablefluid material are disposed surrounding the shell. A second shellencapsulates the first shell, the electrolyte and the curable material.In response to an applied magnetic field, the position of the firstshell is changeable relative to the second shell. Upon curing thecurable material, the position of the first shell relative to the secondshell is locked in place. As is described in detail herein, thismicrocapsule structure can be used to form capacitor/OLED microcapsuleswhich may be particularly effective for use in passive matrix displays.

In accordance with the present invention, a method for forming an OLEDdevice is provided. A top electrode and a bottom electrode are provideddefining a gap there between. Within the gap a field reactive OLEDparticulate is disposed randomly dispersed within a fluid carrier. Analigning field is applied between the top electrode and the bottomelectrode to form a desired orientation of the field reactive OLEDparticulate within the fluid carrier. The fluid carrier comprises ahardenable material. While the desired orientation of the field reactiveOLED particulate is maintained, the carrier is cured to form a hardenedsupport structure within which is locked in position the OLEDparticulate. The OLED particulate may comprise a dielectric OLEDmicrocapsule. The OLED particulate is formed by the steps of firstproviding a first particle comprised of a hole transport material. Thehole transport material has a net first electrical charge. A secondparticle comprised of an electron transport material is provided havinga net second electrical charge. The first electrical charge is ofopposite polarity from the second electrical charge. The first particleand the second particle are brought together to form a unified OLEDparticulate having a hole transport layer and an electron transportlayer forming a heterojunction between them. The first particle mayfurther include a photon-active layer. This photon-active layer may be alight emissive layer in which case the OLED forms a light emittingdevice, or a light receptive layer, in which case the OLED forms a lightdetecting device.

The OLED particulate is formed by microencapsulating an internal phasewithin a shell. The internal phase or the shell includes an OLEDmaterial and either the internal phase or the shell includes a fieldreactive material. The field reactive material comprises either or bothan electrostatic and a magnetically reactive material. In accordancewith another composition of the inventive microcapsule, the internalphase comprises an OLED emitter material and an OLED hole transportmaterial dispersed in solution. Color dyes may also be included withinthe internal phase. The solvent may be a fluid organic solvent. In orderto provide the alignment capabilities of the microcapsules, either theinternal phase or the shell may include a field reactive component.

In accordance with another aspect of the present invention, a stackedOLED device is provided. The inventive OLED device includes a first OLEDpixel layer comprised of a first layer electrode: A second layerelectrode is disposed adjacent to the first layer electrode. A firstlayer gap is defined between the electrodes. An OLED particulate isdispersed within a carrier and contained within the first layer gap. Atleast one subsequent OLED pixel layer is formed over the first OLEDpixel layer. Each subsequent OLED pixel layer includes a firstsubsequent layer electrode. A second subsequent layer electrode isdisposed adjacent to the first subsequent layer electrode defining asecond layer gap there between. An OLED particulate in a carriermaterial is disposed between the electrodes.

To achieve a full color OLED display, the OLED particulate of the firstOLED pixel layer emits light of a first wavelength range in response toa drive voltage being applied to the first layer electrode and thesecond layer electrode. Each subsequent OLED pixel layer emits light ofa different wavelength range in response to the driving voltage appliedto the respective electrode pairs so that an RGB color display can beformed.

Further, a dichromatic pixel layer can be formed adjacent to the lastsubsequent OLED pixel layer. The dichromatic pixel layer can be formedfrom a LCD display layer or from a dichromatic microcapsule displaylayer along the lines described in the U.S. Pat. No. 6,50,687 B1 patentissued to Jacobson, This dichromatic pixel layer, as described fullyherein, results in a display that can viewed in direct bright sunlightas well as with improved contrast in indoor ambient lighting conditions.Further, additional subsequent OLED pixel layers can be provided whichemit light in additional color range having a color and/or lightintensity different from the color and/or light intensity of the otherOLED pixel layers.

Further, the inventive OLED device can be configured so as to detectlight impinging on a pixel grid formed in accordance with the presentinvention. In this case, the OLED particulate of a first OLED pixellayer emits a electrical energy in response to the reception of photonsand applies the electrical energy as a detectable signal to the firstand second layer electrodes. Further, a full color CCD-type camera canbe formed by tuning the wavelength range at which subsequent layers ofOLED pixels are photo reactive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an embodiment of the inventive thin, lightweight,flexible, bright wireless display having components capable of beingmanufactured by the inventive display fabrication method, showing thesimultaneous display of mapped hyperlinked content, a videophone streamand a broadcast TV stream;

FIG. 2 illustrates a particle of OLED material for being dispersed in acarrier fluid in accordance with the inventive display fabricationmethod;

FIG. 3 illustrates an inventive microcapsule comprised of an internalphase of OLED material encapsulated within a polymer shell;

FIG. 4 illustrates an inventive dielectric microcapsule comprised of aninternal phase of OLED material encapsulated within a polymer shell;

FIG. 5 illustrates an inventive microcapsule comprised of a firstmicrocapsule including an internal phase of OLED material and magneticmaterial, along with a mixture of electrolyte and uncured monomer, allencapsulated within a polymer shell;

FIG. 6 illustrates an inventive microcapsule comprised of an internalphase of OLED material encapsulated within a double-wall shell, eachwall having a composition selected for imparting a desired electrical,optical, magnetic and/or mechanical property to the microcapsule;

FIG. 7 illustrates an inventive microcapsule comprised of an internalphase consisting of a mixture of OLED material with other components soas to tailor the electrical, optical, magnetic and/or mechanicalproperty of the microcapsule;

FIG. 8 illustrates an inventive microcapsule comprised of a firstmicrocapsule including an internal phase comprised of an OLED material,and a corrosion barrier material, all encapsulated within a polymershell;

FIG. 9 illustrates an inventive microcapsule comprised of a multi-walledmicrocapsule structure wherein layers of corrosion barrier material areencapsulated within polymer shells with an internal phase of OLEDmaterial;

FIG. 10 illustrates an inkjet-type or other nozzle fabrication methodfor forming a layer of OLED microcapsules dispersed within a lightcurable monomer carrier;

FIG. 11 illustrates a layer of OLED microcapsules fixed within a curedmonomer barrier disposed between a top electrode and a bottom electrode;

FIG. 12 illustrates sealed fabrication stations for forming a barrierprotected OLED microcapsule display stratum;

FIG. 13 illustrates an inventive display fabrication line using modularprinters for forming various stratum of a thin, lightweight, flexiblewireless display;

FIG. 14 illustrates a highly organized OLED microcapsule structureformed in accordance with the inventive OLED device fabrication method;

FIG. 15 illustrates a chain structure of OLED microcapsules formed inaccordance with the inventive OLED device fabrication method;

FIG. 16 illustrates a full color OLED display formed in accordance withthe inventive OLED device fabrication method;

FIG. 17 illustrates a layer of conductive microcapsules for forming anelectrode layer in accordance with the inventive device fabricationmethod;

FIG. 18 illustrates the formation of OLED microcapsule chains formed onan electrode layer;

FIG. 19 illustrates the formation of OLED microcapsule chains formedbetween top and bottom electrode layers;

FIG. 20 illustrates the formation of OLED microcapsule chains within acured carrier for forming a corrosion barrier;

FIG. 21 illustrates a full color display formed in accordance with theinventive OLED device fabrication method;

FIG. 22 illustrates step one of an embodiment of the inventive OLEDdevice fabrication method;

FIG. 23 illustrates step two of an embodiment of the inventive OLEDdevice fabrication method;

FIG. 24 illustrates step three of an embodiment of the inventive OLEDdevice fabrication method;

FIG. 25 illustrates step four of an embodiment of the inventive OLEDdevice fabrication method;

FIG. 26 illustrates step five of an embodiment of the inventive OLEDdevice fabrication method;

FIG. 27 illustrates step six of an embodiment of the inventive OLEDdevice fabrication method;

FIG. 28 shows a magnetically reactive OLED microcapsule for forming acapacitor OLED microcapsule with the aligning field turned off;

FIG. 29 shows a magnetically reactive OLED microcapsule for forming acapacitor OLED microcapsule with the magnetic aligning field turned onwith uncured electrolyte mixture;

FIG. 30 shows a magnetically reactive OLED microcapsule for forming acapacitor OLED microcapsule with the magnetic aligning field turned onwith cured electrolyte mixture;

FIG. 31 shows a pixel comprised of a chain of capacitor OLED beingcharged by a charging voltage;

FIG. 32 shows a pixel comprised of a chain of capacitor OLED beingtriggered for light emission by a trigger voltage;

FIG. 33 shows OLED microcapsules randomly dispersed within a fluid buthardenable carrier fluid;

FIG. 34 shows OLED microcapsule chains aligned within an appliedaligning field formed within unhardened carrier fluid;

FIG. 35 shows OLED microcapsule chains aligned within an appliedaligning field held in alignment within hardened carrier;

FIG. 36 shows the OLED microcapsule structure shown in FIG. 35 with adrive voltage applied and light being emitted from the OLED microcapsulechains;

FIG. 37 illustrates a method for forming an OLED particulate having ahole transport layer and an electron transport layer;

FIG. 38 illustrates a method for forming an encapsulated OLEDparticulate;

FIG. 39 illustrates a first step in forming a multi-layered OLEDparticulate;

FIG. 40 illustrates a second step in forming a multi-layered OLEDparticulate;

FIG. 41 illustrates a third step in forming a multi-layered OLEDparticulate;

FIG. 42 schematically shows a full-color OLED display constructed inaccordance with the present invention, and having a dichromatic displaylayer for improving the display contrast, power efficiency and forproviding display viewing in bright sunlight;

FIG. 43 schematically shows the full-color OLED display shown in FIG.42, with the dichromatic pixels oriented for reflecting emitted OLEDlight;

FIG. 44 schematically shows the full-color OLED display shown in FIG.42, showing the relative strength of reflected light depending on thedichromatic pixel orientations;

FIG. 45 shows magnetically-active OLED microcapsules randomly dispersedwithin a fluid but hardenable carrier fluid along with desiccantparticulate;

FIG. 46 shows the magnetically-active OLED microcapsule chains alignedwithin an applied magnetic aligning field within the unhardened carrierfluid;

FIG. 47 shows the magnetically-active OLED microcapsule chains alignedwithin the applied magnetic aligning field held in position within thehardened carrier;

FIG. 48 shows the magnetically-active OLED microcapsule structure withlight being emitted from the OLED microcapsule chains;

FIG. 49 schematically illustrates a full color OLED display having highintensity visible light display layers and an infrared display layer;

FIG. 50 shows an OLED display layer and a liquid crystal display layer;

FIG. 51 shows an inventive OLED display fabricated with thin films oforganic material with photodetection elements and photodetection pixelelements;

FIG. 52 shows an OLED microcapsule wherein the shell is slightly lessconductive than the encapsulated OLED material;

FIG. 53 shows an OLED microcapsule wherein the OLED material isencapsulated along with an electrolyte and a magnetic inner microcapsulehaving an electrically insulative shell;

FIG. 54 shows an OLED microcapsule wherein the OLED material and thehole transport material are contained in solution within a conductiveshell;

FIG. 55 shows the OLED microcapsules shown in FIG. 54 including amagnetically active material and color dye in the inner phase and heatmeltable material in the shell;

FIG. 56 illustrates the OLED microcapsule shown in FIG. 54 used forcreating a general lighting or display back lighting OLED device;

FIG. 57 illustrates a transparent, flexible OLED display fabricated foruse as part of a vehicle windshield;

FIG. 58 is a block diagram showing the basic components of an activewindshield display system using an OLED display;

FIG. 59 illustrates an OLED light emissive element;

FIG. 60 shows the OLED light emissive element having a conventionallight bulb form factor;

FIG. 61 illustrates an OLED device fabricated using light emissivelayers and light detecting layers;

FIG. 62 illustrates stereoscopic goggles having OLED device elements;

FIG. 63 illustrates a flexible OLED display having a curvature thecompensates for the human eye's range of motion;

FIG. 64 illustrates a flexible OLED display having optical lens elementsfor focusing emitted light at the appropriate physical location within ahuman eye;

FIG. 65 illustrates a wraparound visor having a curved, flexible OLEDdisplay and speakers;

FIG. 66 illustrates a wall of a house having an inventive OLED displaywindow, the window being driven so as to be transparent with treesoutside the house visible through the window;

FIG. 67 illustrates the wall of a house having the inventive OLEDdisplay window, the window being driven so as to display multiplesimultaneous video stream including video phone communication, Internetweb page and a television program;

FIG. 68 illustrates the wall of a house having the inventive OLEDdisplay window, the window being driven so as to be a mirror.

FIG. 69 illustrates an embodiment of the inventive light active deviceshowing a semiconductor particulate randomly dispersed within aconductive carrier;

FIG. 70 illustrates an embodiment of the inventive light active deviceshowing the semiconductor particulate aligned between electrodes;

FIG. 71 illustrates an embodiment of the inventive light active deviceshowing semiconductor particulate and other performance enhancingparticulate randomly dispersed within the conductive carrier material;

FIG. 72 illustrates an embodiment of the inventive light active deviceshowing different species of organic light active particulate dispersedwithin a carrier material;

FIG. 73 illustrates an organic light active particle formed from apolymer blend;

FIG. 74 illustrates the polymer blend organic light active particulatedispersed within a conductive carrier;

FIG. 75 illustrates the polymer blend organic light active particleshowing light active sites;

FIG. 76 illustrates a polymer blend organic light active particulatehaving a field attractive constituent for aligning the particle in analigning field;

FIG. 77 illustrates composite microcapsules containing multilayeredorganic light active particles, each having a different light wavelengthemission and turn-on voltage;

FIG. 78 illustrates another composite microcapsule containingmultilayered organic light active particles, at least one having a fieldattractive constituent;

FIG. 79 illustrates three light emitting microcapsule species, eachspecies having a turn-on voltage controlled by the internal phasecomposition and the encapsulating shell composition;

FIG. 80 illustrates an embodiment of the inventive voltage controlledlight active device showing the composite microcapsule particulaterandomly dispersed within a carrier;

FIG. 81 illustrates an embodiment of the inventive voltage controlledlight active device showing the composite microcapsule particulatealigned between electrodes;

FIG. 82 illustrates the retinal response of the human eye to wavelengthsof light in the visible spectrum;

FIG. 83 illustrates the inventive primary color burst driving method forproducing a perceived full color image by the rapid and sequentialbursts of primary colored light emission;

FIG. 84 illustrates the inventive retinex burst driving method forproducing a perceived full color image by the rapid and sequentialbursts of colored light emission;

FIG. 85 illustrates the inventive adjusted color burst driving methodfor producing a perceived full color image by the rapid and sequentialbursts of adjusted colored light emission;

FIG. 86 is a flow chart showing the steps of the inventive method forforming a multilayered organic light active material particulate;

FIG. 87 illustrates a layered organic light active material particulateformed by the commingling of a particle of hole transport material witha particle of emissive layer material;

FIG. 88 illustrates the inventive method of forming a layered organiclight active material particulate from a hole transport constituent andan emissive layer constituent;

FIG. 89 illustrates a multi-layered organic light active materialparticulate formed by the commingling of a layered particle of holetransport/emissive layer material with a particle of electron transportmaterial;

FIG. 90 illustrates the inventive method of forming a multi-layeredorganic light active material particulate from a hole transport/emissivelayer constituent and an electron transport constituent;

FIG. 91 illustrates a layered organic light active material particulateformed by the commingling of a particle of blocking material with aparticle of electron transport material;

FIG. 92 illustrates the inventive method of forming a layered organiclight active material particulate from a blocking constituent and anelectron transport constituent;

FIG. 93 illustrates a layered organic light active material particulateformed by the commingling of a particle of emissive layer material witha particle of hole transport material;

FIG. 94 illustrates the inventive method of forming a layered organiclight active material particulate from an emissive layer constituent anda hole transport constituent;

FIG. 95 illustrates a multi-layered organic light active materialparticulate formed by the commingling of a layered particle ofblocking/electron transport material with a layered particle of emissivelayer/hole transport material;

FIG. 96 illustrates the inventive method of forming a multi-layeredorganic light active material particulate from a blocking/electrontransport constituent and a hole transport/emissive layer constituent;

FIG. 97 illustrates a layered organic light active material particulateformed by the commingling of a particle of field attractive materialwith a particle of electron transport material;

FIG. 98 illustrates the inventive method of forming a layered organiclight active material particulate from a field attractive constituentand an electron transport constituent;

FIG. 99 illustrates a layered organic light active material particulateformed by the commingling of a particle of emissive layer material witha particle of hole transport material;

FIG. 100 illustrates the inventive method of forming a layered organiclight active material particulate from an emissive layer constituent anda hole transport constituent;

FIG. 101 illustrates a multi-layered organic light active materialparticulate formed by the commingling of a layered particle of fieldattractive/electron transport material with a layered particle ofemissive layer/hole transport material;

FIG. 102 illustrates the inventive method of forming a multi-layeredorganic light active material particulate from a fieldattractive/electron transport constituent and a hole transport/emissivelayer constituent;

FIG. 103 is a cross section of a coated cathode fiber having a blockinglayer formed on the cathode fiber and an electron transport layer formedon the blocking layer;

FIG. 104 is a cross section of a coated anode fiber having a holetransport layer formed on the anode fiber and an emissive layer formedon the hole transport layer;

FIG. 105 illustrated the coated cathode fiber and the coated anode fibertwisted together to form an emissive fiber; and

FIG. 106 shows a method for coating an electrode wire with organic lightactive device material.

DETAILED DESCRIPTION OF THE INVENTION

For purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended, there being contemplated such alterationsand modifications of the illustrated device, and such furtherapplications of the principles of the invention as disclosed herein, aswould normally occur to one skilled in the art to which the inventionpertains.

FIG. 1 illustrates an embodiment of the inventive thin, lightweight,flexible, bright wireless display having components capable of beingmanufactured by the inventive display fabrication method, showing thesimultaneous display of mapped hyperlinked content, a videophone streamand a broadcast TV stream. FIG. 1 illustrates an embodiment of aninventive thin, lightweight, flexible, bright, wireless display showingthe simultaneous display of three received display signal. The inventivethin, lightweight, flexible, bright, wireless display includes aflexible substrate 24 to provide a support structure upon whichcomponents can be manufactured by a fabrication method. As described inthe co-owned U.S. patent application Ser. No. 10/234,302, entitled “AThin, Lightweight, Flexible, Bright, Wireless Display”, the disclosureof which is incorporated by reference herein, a unique and effectivemethod for transmitting display information to a single or multipledisplays enables such displays to not have to have substantial onboardstorage or processing power. In accordance with this aspect of theinvention, the energy drain, bulk, weight and cost normally associatedwith such devices is avoided; and the durability and convenience of thedisplay is increased. Further, as shown schematically in FIG. 1,multiple streams of display information can be simultaneously receivedand displayed. For example, broadcast video content such as a televisionprogram may be shown at a first portion of the display, personalizedvideo content, such as a videophone conversation may be shown at asecond portion and a web page, including mapped hyperlink content, maybe shown at a third portion. Most of the processing, networking, signaltuning, data storage, etc., etc., that it takes to create such a set ofdisplayed content streams is not performed by the inventive wirelessdisplay. Other devices, such as a centralized computer, A/V or gatewaydevice perform these functions thus allowing the opportunity for theinventive display to have tremendous mobility and convenience.

FIG. 1 illustrates an embodiment of the inventive thin, lightweight,flexible, bright wireless display having components capable of beingmanufactured by the inventive fabrication method, showing thesimultaneous display of mapped hyperlinked content, a videophone streamand a broadcast TV stream. In accordance with the present invention, athin, lightweight, flexible, bright wireless display is obtained havingcomponents capable of being manufactured by the inventive fabricationmethod. The present invention enables a low cost, flexible, robust, fullcolor video display to be obtained. This wireless display is capable ofreceiving multiple display information signals and displaying thesimultaneous screens of the received display information inre-configurable formats. A relatively simple signal receiving andprocessing circuit, using, for example, a digital signal processor suchas those available from Texas Instruments, Texas or Oxford Microdevices,Connecticut, enables multiple video and still image screens to bedisplayed. An inventive manufacturing method described herein and in theco-owned patent application entitled “Printer and Method forManufacturing Electronic Circuits and Displays” (incorporated byreference herein) enables the inventive wireless display to befabricated at low cost and with the advantageous features describedherein. As described in more detail herein, a flexible substrate 24provides a support structure upon which components can be manufacturedby a fabrication method. A display stratum includes light emittingpixels for displaying information. The light emitting pixels are formed,by printing a pixel layer of light-emitting conductive polymer. Anelectronic circuit stratum includes signal transmitting components fortransmitting user input signals to a display signal generating devicefor controlling display information transmitted from the display signalgenerating device. Signal receiving components receive the displayinformation transmitted from the display signal-generating device.Display driving components drive the display layer according to thereceived display information. A user input stratum receives user inputand generates the user input signals. A battery stratum provideselectrical energy to the electronic circuit stratum, the user inputstratum and display stratum components. The signal receiving componentsmay include first radio frequency receiving components for receiving afirst display signal having first display information carried on a firstradio frequency and second radio frequency receiving components forreceiving a second display signal having second display informationcarried on a second radio frequency. The display driving components mayinclude signal processor components for receiving the first displaysignal and the second display signal and generating a display drivingsignal for simultaneously displaying the first display information at afirst location on the display stratum and the second display informationat a second location on the display stratum. At least some of thecomponents in the battery, display, user input and electronic circuitstratums are formed by printing electrically active material to formcircuit elements including resistors, capacitors, inductors, antennas,conductors and semiconductor devices.

The inventive thin, lightweight, wireless display includes OLAMfabrication, such as that described herein. In accordance with thepresent invention, microcapsule 10 particulate are randomly dispersedwithin a monomer carrier fluid 12 that is injected or otherwise disposedbetween two electrodes 14. The term particulate can refer to particlesof material or microcapsules 10. The microcapsules 10 may includeadditives that impart rheological properties. The microcapsules 10 formchains between the electrodes 14 when a voltage is applied. Holding thevoltage to keep the chains formed, the carrier fluid 12 is polymerizedand the OLAM microcapsule chains locked into alignment between theelectrodes 14. The thus formed OLAM pixels emit light (or detect orconvert light into electricity). The problem of contamination of theOLAM material is the major factor limiting the display life span, andthus is a bar to commercial success. The inventive fabrication methodresults in the corrosion sensitive OLAM material being protected by themicrocapsule shell and the cured carrier 12. The pixel alignment isautomatic, since the microcapsule chains are formed only between theelectrodes 14. This pixel array structure also greatly limits cross talkbetween pixels and the optical properties of the cured monomer can becontrolled to improve contrast, display brightness, transparency, etc.

Solar cell components or layers can be used to “recycle” the energyemitted by the OLED emitters. Some of the emitted and ambient lightenergy impinges on the solar cells and generate electricity. This, alongwith the inventions described herein and the sheet battery described inthe above-referenced co-owned Patent Applicant entitled “Printer andMethod for Manufacturing Electronic Circuits and Displays”, can enablelightweight, relatively inexpensive, dichromatic newspapers (asdescribed herein in FIG. 1) that recharge in sunlight (or even indoorambient light) to enable full-color emissive video display.

FIG. 2 illustrates a particle of OLED material for being dispersed in acarrier fluid 12 in accordance with the inventive display fabricationmethod. A typical OLED organic stack consists of a layer of holetransport material and a layer of electron transport material. In theconventional art, these layers are formed by spin coating, vacuumdeposition or ink-jet printing. In accordance with the presentinvention, the OLED material is provided as particulate dispersed withina carrier 12 material. The carrier 12 material with the dispersedparticulate is disposed between electrodes 14. Electrical potentialapplied to the electrodes 14 causes light emission to occur within theOLED particulate. In accordance with the present invention, the OLEDphenomenon can be used to create general or specialty lighting devices,monochrome or color displays, stereoscopic vision aids, digital maps andnewspapers, advanced vehicle windshields and the like. Also, theparticulate can be organic light active material (“OLAM™”) that iscapable of generating a flow of electrons in response to impinging lightenergy. This phenomenon can be used to create photodetectors, cameras,solar cells and the like. In this application, where appropriate, theterm OLED can mean a light emissive or a light detective materialconfiguration.

FIG. 3 illustrates an inventive microcapsule 10 comprised of an internalphase of OLAM material encapsulated within a polymer shell. To create apath of least resistance through the OLED material, the shellcomposition is selected to be less conductive than the OLED material.

FIG. 4 illustrates an inventive electrostatically active microcapsulecomprised of an internal phase of OLED material encapsulated within apolymer shell. The shell is composed of a material that can be orientedby the application of an electric field. The electrical properties ofthe shell enable the microcapsules 10 to be aligned into a desiredformation within a fluid carrier 12 in response to an applied electricfield.

FIG. 5 illustrates an inventive microcapsule 10 comprised of a firstmicrocapsule 10 including an internal phase of OLED material andmagnetic material, along with a mixture of electrolyte and uncuredmonomer, all encapsulated within a polymer shell. The magneticproperties of the magnetic material enable the microcapsules 10 to bealigned into a desired formation within a fluid carrier 12 in responseto an applied magnetic field.

FIG. 6 illustrates an inventive microcapsule 10 comprised of an internalphase of OLED material encapsulated within a double-wall shell, eachwall having a composition selected for imparting a desired electrical,optical, magnetic and/or mechanical property to the microcapsule. Inaccordance with the present invention, the OLED particulate comprisesmicrocapsules 10. For example, the microcapsule 10 includes an internalphase and a shell that is composed of material selected according to adesired combination of electrical, mechanical, optical and magneticproperties. The internal phase and/or the shell may include the OLEDmaterial. The internal phase and/or the shell may also include a fieldreactive material. Depending on the OLED fabrication method and thedesire OLED characteristics, the field reactive material may be anelectrostatic material and/or a magnetically reactive material. Themicrocapsule 10 composition may be effective for enabling a “selfhealing” capability of the fabricated OLED device. In this case, themicrocapsule 10 includes a composition that causes the microcapsule 10to rupture if electrical energy above a threshold is applied to themicrocapsule. A heat meltable material that heats up when electricalenergy above a threshold is applied can be incorporated as themicrocapsule shell. For example, if a particular microcapsule 10 ends uppositioned so that during use of the OLED device it becomes a shortbetween the electrodes 14, or if the microcapsule 10 is adjacent to adust particle or other foreign inclusion, creating such a short, when anelectric potential is applied between the electrodes 14, energyexceeding a predetermined threshold will pass through the microcapsule10 causing the capsule to rupture and disconnect the short. By thisconstruction, the microcapsule 10 is automatically removed from the pathof conduction of electrical energy in the event of a short.

FIG. 7 illustrates an inventive microcapsule 10 comprised of an internalphase consisting of a mixture of OLED material with other components soas to tailor the electrical, optical, magnetic and/or mechanicalproperty of the microcapsule. The other components can be fieldreactive, such as magnetic or electrostatically reactive materials forimparting orientation and aligning properties. Heat expandable materialscan be included to provide the microcapsule 10 with the ability to burstin response to an electrical short to disconnect the microcapsule 10 andovercome the electrical short. Colorants, such as dyes and coloredparticles can be included to tune the light emitted from themicrocapsule. Desiccant material can be included to provide protectionagainst contamination of the OLED material.

FIG. 8 illustrates an inventive microcapsule 10 comprised of a firstmicrocapsule 10 including an internal phase comprised of an OLEDmaterial, and a corrosion barrier material, all encapsulated within apolymer shell. In accordance with this aspect of the invention, themicrocapsule shell and/or internal phase may include a compositioneffective to provide a barrier against degradation of the OLED material.The OLED microcapsules 10 are dispersed within a carrier fluid 12. Thiscarrier fluid 12 also provides a barrier against the intrusion ofsubstances which degrade the OLED material.

FIG. 9 illustrates an inventive microcapsule 10 comprised of amulti-walled microcapsule 10 structure wherein layers of corrosionbarrier material are encapsulated within polymer shells with an internalphase of OLED material. As in the microcapsule 10 shown in FIG. 7,within the shell of the microcapsule 10 other components can be includedthat are field reactive, such as magnetic or electro-statically reactivematerials for imparting orientation and aligning properties. Heatexpandable materials can be included to provide the microcapsule 10 withthe ability to burst in response to an electrical short to disconnectthe microcapsule 10 and overcome the electrical short. Colorants, suchas dyes and colored particles can be included to tune the light emittedfrom the microcapsule. Desiccant material can be included to provideprotection against contamination of the OLED material.

FIG. 10 illustrates an inkjet-type or other nozzle 36 fabrication methodfor forming a layer of OLED microcapsules 10 dispersed within a lightcurable monomer carrier 12. OLED microcapsules 10 dispersed in anuncured monomer carrier fluid 12 can be utilized with inkjet printingtechnology to create a film of OLED microcapsules 10 contained withflexible cured monomer. The inkjet-type or other nozzle fabricationtechnique can be utilized to form controlled OLED deposition, with theOLED contained within a curable carrier 12. As is described elsewhereherein, desiccant particulate can be included within the carrier 12 toenhance the protection of the OLED material.

FIG. 11 illustrates a layer of OLED microcapsules 10 fixed within acured monomer barrier disposed between a top electrode 14 and a bottomelectrode 14. The cured monomer and the shell of the microcapsules 10provide a barrier to contamination from water vapor and oxygen. The OLEDdevice can be constructed of suitably chosen materials so that thecarrier 12 material is relatively less electrically conductive than theOLED particulate, this ensures that the OLED particulate offers a pathof less electrical resistance than the carrier 12 material. Thus, theelectric potential applied to the electrodes 14 will pass through thecarrier 12 material, which has some electrical conductivity, and throughthe OLED particulate, which has relatively higher electricalconductivity. In this way, the preferred path of electrical conductionis through the OLED particulate. Likewise, the shell of the OLEDmicrocapsules 10 is relatively less electrically conductive than theOLED material itself, so that the OLED material offers a path of lesselectrical resistance than the shell. Field-attractive microcapsules 10containing OLED material randomly dispersed within a monomer carrierfluid 12 are injected or otherwise disposed between two electrodes 14.The microcapsules 10 may include additives that impart electro ormagneto rheological-type properties. When used for a pixilated displaylayer, the microcapsules 10 form chains between the electrodes 14 when aaligning field is applied. Holding the aligning field to keep the chainsformed, the carrier fluid 12 is polymerized and the OLED microcapsulechains are locked into alignment between the electrodes 14.

The problem of contamination of the OLED material is the major factorlimiting the display life span, and thus is a bar to commercial success.The inventive fabrication method results in the corrosion sensitive OLEDmaterial being protected by the microcapsule shell and the cured carrier12, and the pixel alignment is automatic, since the microcapsule chainsare formed only between the electrodes 14 or where the aligning field isapplied. This pixel array structure also greatly limits cross talkbetween pixels and the optical properties of the cured carrier 12 can becontrolled to improve contrast, display brightness, transparency, etc.The OLED particulate in a carrier 12 disposed between two or moreelectrodes 14 can be utilized to create roll-to-roll sheets of displaysor lights, used as “filament” in a light bulb, used to form solar cells,solar cell housing shingles, light detectors, cameras, vision aides,heads-up display windshields and the like. This OLAM construction caneven be formed as fibers for light emitting flooring, wall coverings,specialty lighting, clothing, shoes, building materials, furniture, etc.

FIG. 12 illustrates sealed fabrication stations 22 for forming a barrierprotected OLED microcapsule 10 display stratum. The microcapsules 10 aredispersed in a carrier fluid 12. The upper and lower plate 16 s, controlthe intensity of the attraction toward the flexible substrate 24 andsheet electrode 14. Seals 18 keep out water and air, using a vacuumairlock. The curing station 20 cures the carrier fluid 12 into aflexible water and oxygen barrier. The microcapsules 10 can be forforming emitters, detectors, various electronic circuit elements (asdescribed in the referenced co-owned patent application). Themicrocapsules 10 may also be for adding other mechanical (structure,expansive, meltable, desiccant, etc.), optical (reflective, diffusive,opaque, colorant, etc.), electrical (conductive, resistive,semi-conductive, insulative, etc.). The upper and lower plate 16 s arecontrolled to vary the attractive and/or aligning field and createcontrolled accumulations and alignments of the microcapsules 10. Theviscosity of the fluid can also be controlled to control theaccumulations of microcapsules 10 (for three-dimensional buildup,control spread of pixels, etc.). As an example, lower viscosity carrierfluid 12 with an agitator may be preferred. There can be, for example,two simultaneously applied aligning fields, magnetic and electrostatic.A mix of microcapsules 10 can be dispersed, (e.g., magnetically andconductive OLED microcapsules 10 and electrostatically conductiveinsulators for creating a more controllable path of least resistance).

FIG. 13 illustrates an inventive display fabrication line using modularprinters for forming various stratum of a thin, lightweight, flexiblewireless display. Display fabrication line uses mix of differentfabrication stations 22. Examples of fabrication stations 22 can befound in co-owned U.S. patent application Ser. No. 10/234,301 entitled“Printer and Method for Manufacturing Electronic Circuits and Displays”.The various layers of a display include battery, electronic circuit,user input and display stratums are formed at different fabricationstations 22. In accordance with the present invention, fabricationstations 22 for forming an OLED light emissive device is provided. A topelectrode 14 and a bottom electrode 14 define a gap there between.Disposed within the gap, field reactive OLED particulates are randomlydispersed within a fluid carrier 12. Depending on the device beingfabricated, an aligning field may be applied between the top electrode14 and the bottom electrode 14 to form a desired orientation of thefield reactive OLED particulate within the fluid carrier 12 between thetop electrode 14 and the bottom electrode 14. The carrier 12 comprises ahardenable material, such as a light-curable liquid monomer. The carrier12 is cured to form a hardened carrier 12 for maintaining the desiredorientation of the field reactive OLED particulate within the hardenedcarrier 12. The OLED particulate may comprise a dielectric OLEDmicrocapsule 10 or other OLED-based structure that is capable of formingchains between the electrodes 14.

Depending on the quality of the barrier created by the inventivefabrication method, there may be no need for additional barrier layers30 other than substrates 24 since cured carrier 12 and microcapsuleshells protect OLED material from water vapor and oxygen. Alternatively,addition barrier layers 30, including monomer, polymer, ceramic or thinmetal layers can be included in the structure as needed to protect theOLED material from contamination. Each color layer can be built on theprevious by fabrication method. The conductors 26 that make up the pixelelectrodes 14 can also be used to fabricate the OLED microcapsule 10structure. In this case the substrate 24 and pixel electrode 14 gridbecome integral parts of the completed OLED device. Further, theelectric field created by applying voltage to the electrodes 14 can beused to align the OLED microcapsules 10 in chains as shown elsewhereherein. The mechanism for this alignment is similar to the phenomenonthat causes electro-rheological fluids to form chains within a carrierfluid 12. In this case, the OLED microcapsule 10 or the OLED particleitself includes the appropriate material component that enables theelectro-rheological effect. In addition, or alternatively, magneticmaterial can be employed with a magnetic field being applied as thealigning field. The light emitted from the OLED material when energizedby the applied voltage can be used cure the monomer surrounding themicrocapsules 10. Thus, the voltage applied to the electrodes 14 duringdevice fabrication are utilized to form the pixel orientation andsimultaneously cure the barrier material.

FIG. 14 illustrates a highly organized OLED microcapsule 10 structureformed in accordance with the inventive OLED device fabrication method.Pixels can be controlled down to the microcapsule 10 size, spaced apartas needed. The conductive shell having a semi-insulative orsemi-conductive electrical property. The insulative or semiconductorshell creates a preferred path for the electron movement. By controllingthe conductivity of the cured carrier fluid 12, the preferred path canbe more pronounced through the OLED material.

FIG. 15 illustrates a chain structure of OLED microcapsules 10 formed inaccordance with the inventive OLED device fabrication method. Chains ofmicrocapsules 10 can be formed encased in opaque cured carrier 12,creating more intense light and defined pixels, or the carrier 12 can bean optical diffusion layer to create a mixing of light from adjacentpixels. In accordance with the present invention, an OLED deviceincludes a first electrode 14 and a second electrode 14. The secondelectrode 14 is disposed adjacent to the first electrode 14 so that agap is defined between them. An OLED particulate is dispersed within acarrier 12 material, which is disposed within the gap. When an electricpotential is applied to the electrodes 14, the electrical energy passesthrough the carrier 12 material raising the energy state of the OLEDparticulate, resulting in the emission of light. The typical OLEDincludes an OLED component that is a hole transport material and an OLEDcomponent that is an electron transport material. In accordance with aformulation of the inventive microcapsules 10, the shell comprises anOLED component material that is either the hole transport material orthe electron transport material, and the internal phase of themicrocapsule 10 includes the OLED component material that is the otherof the hole transport material or the electron transport material.Depending on the desired optical qualities of the fabricated OLEDdevice, the carrier 12 material can be selected so that it has opticalproperties during use of the OLED device that are transparent,diffusive, absorptive, and/or reflective to light energy.

FIG. 16 illustrates a full color OLED display formed in accordance withthe inventive OLED device fabrication method. The inventive microcapsule10 fabrication is used to create a full color emissive display. Pixelscan be controlled down to the microcapsule 10 size, spaced apart asneeded. The conductive shell can have a semi-conductive, conductive oran insulative over shell. The composition creates a preferred path forthe electron movement. By controlling the conductivity of the curedcarrier fluid 12, the preferred path can be more pronounced. Theinventive OLED device includes a first OLED pixel layer comprised of afirst layer electrode 14. A second layer electrode 14 is disposedadjacent to the first layer electrode 14. A first layer gap is definedbetween the electrodes 14. An OLED particulate is dispersed within acarrier 12 and contained within the first layer gap. At least onesubsequent OLED pixel layer is formed over the first OLED pixel layer.Each subsequent OLED pixel layer includes a first subsequent layerelectrode 14. A second subsequent layer electrode 14 is disposedadjacent to the first subsequent layer electrode 14 defining a secondlayer gap there between. An OLED particulate in a carrier 12 material isdisposed between the electrodes 14. To achieve a full color OLEDdisplay, the OLED particulate of the first OLED pixel layer emits lightof a first wavelength range in response to a drive voltage being appliedto the first layer electrode 14 and the second layer electrode 14. Eachsubsequent OLED pixel layer emits light of a different wavelength rangein response to the driving voltage applied to the respective electrode14 pairs so that an RGB color display can be formed.

FIG. 17 illustrates a layer of conductive microcapsules 10 for formingan electrode 14 layer in accordance with the inventive devicefabrication method. The buildup of microcapsule 10 layers may occur insuccessive fabrication steps. The conductor 26 may be microencapsulated,or just a field attractive material. For example, a ferrous metal powdercan be magnetically attracted to form one or more of the conductors. TheOLED microcapsule 10 can be electrostatic or magnetically attractive.The carrier 12 substrate 24 has to pass the applied field. The carrierfluid 12 is heat or light hardenable by light emitted from a curinglight source 28 to lock the microcapsules 10 in place. Alternatively,the carrier fluid 12 can be a plastic material capable of beinginjection molded, or a multi-part mixture such as an epoxy, a conductivepowder and a hardener.

FIG. 18 illustrates the formation of OLED microcapsule chains formed onan electrode 14 layer. Conductive pixels can be etched into optomagneticor optoelectric coating to improve resolution. Or the location of thepixel that is energized can be controlled by light or laser pulse orother mechanism. The light curable polymer can be cured to a desireddepth to capture the microcapsules 10 that have been attracted, and thuslock in, for example, a microcapsule chain having a desired length.

FIG. 19 illustrates the formation of OLED microcapsule chains formedbetween top and bottom electrode layers. The electrodes 14 can be formedin previous fabrication steps, and may be attracted by a mechanism otherthan the mechanism that orients the OLED particulate.

FIG. 20 illustrates the formation of OLED microcapsule chains within acured carrier 12 for forming a corrosion barrier. The substrate 24 uponwhich the microcapsules 10 are printed may be a multi-layeredcomposition of polymer, cured monomer, ceramic and fiber, such as glass,creating a durable, flexible substrate 24 that is also a barrier tocorrosion for the OLED (as is the microcapsule shell and the curedcarrier fluid 12). The conductors 26 that make up the pixel electrodes14 can also be used to apply the aligning field used to fabricate theOLED microcapsule 10 structure.

FIG. 21 illustrates a full color display formed in accordance with theinventive OLED device fabrication method. Depending on the quality ofthe barrier created by the inventive fabrication method, there may be noneed for additional barrier layers 30 other than substrates 24 sincecured carrier 12 and microcapsule shells protect the OLED material fromwater vapor and oxygen. Alternatively, additional barrier layers 30,including monomer, polymer, ceramic, fiber, desiccant and/or thin metallayers can be included in the structure as needed to protect the OLEDmaterial from contamination. Each color layer can be built on theprevious, by a fabrication station. The conductors 26 that make up thepixel electrodes 14 can also be used to fabricate the OLED microcapsulestructure. In this case, the substrate 24 and pixel electrode gridbecome integral parts of the completed OLED device. The electric fieldcreated by applying voltage to the electrodes 14 can be used to alignthe OLED microcapsules 10 in chains as shown elsewhere herein. Themechanism for this alignment is similar to the phenomenon that causeselectro-rheological fluids to form chains within a carrier fluid 12. Inthis case, the OLED microcapsule 10 or the OLED particle itself includesthe appropriate material component that enables the rheological effect(i.e., the movement of the OLED particulate within the carrier). Inaddition, or alternatively, magnetic material can be used with amagnetic field being applied as the aligning field. The light emittedfrom the OLED material when energized by the applied driving voltage canbe used to cure the monomer surrounding the microcapsules 10. Thus, thevoltage applied to the electrodes 14 during device fabrication can beutilized to form the pixel orientation and simultaneously cure thebarrier material.

FIGS. 22-27 illustrate the steps for forming an OLED device inaccordance with an embodiment of the present invention. FIG. 22illustrates step one of an embodiment of the inventive OLED devicefabrication method. Step One: Provide Top and Bottom FlexibleSubstrates. Step Two: Form Barrier layers 30 on Top and Bottom FlexibleSubstrates 24 (FIG. 23). Step Three: Form Top and Bottom Electrodes 14on Barrier layer 30 (FIG. 24). Step Four: Fill Void between Top andBottom Electrode 14 with OLED microcapsules 10 dispersed in uncuredcarrier fluid 12 (FIG. 25). Step Five: Apply potential to electrodes 14to organize OLED microcapsules 10 into chains (FIG. 26). Step Six: Curecarrier 12 to lock OLED microcapsule chains between the electrodes 14 toform pixels (FIG. 27). The composition of the OLED particulate can beselected so that the characteristics of the OLED particulate includes anelectro or magneto rheological characteristic. This rheologicalcharacteristic is effective for causing the OLED particulate to orientin an applied aligning field.

FIG. 28 shows a magnetically reactive OLED microcapsule 10 for forming acapacitor OLED microcapsule 10 with the aligning field from an aligningfield source 32 turned off. An OLED microcapsule 10 is formed having acapacitor capability. An OLED material internal phase is encapsulatedwithin a first shell. An electrolyte surrounds the first shell and asecond shell encapsulates the first shell and the electrolyte. The OLEDmaterial internal phase includes a field reactive material. The fieldreactive material comprises at least one of a magnetically reactivematerial and an electrically reactive material effective to orient theOLED microcapsule 10 within an aligning field applied from the aligningfield source 32. By this construction, OLED material and fieldattractive material, such as magnetic material, are microencapsulatedwithin an electrically conductive shell, forming an OLED/Mag internalcore. The OLED/Mag internal core is microencapsulated along with amixture of electrolyte and light curable monomer liquid phase within asecond electrically conductive shell. The microcapsule shell material isselected to have the appropriate breakdown voltage at which chargeconduction occurs. The microcapsules 10 act as capacitor elements thatare charged up with a charging voltage. A trigger voltage is thenapplied when the OLED pixel is to emit light.

FIGS. 28-30 illustrate the formation of an OLED/Capacitor microcapsule.OLED material and field attractive material, such as magnetic material,are microencapsulated within an electrically conductive shell, formingan OLED/Mag core. The OLED/Mag core is microencapsulated along with amixture of electrolyte and light curable monomer liquid phase within asecond electrically conductive shell. The microcapsule shell material isselected to have the appropriate breakdown voltage at which chargeconduction occurs. FIG. 29 shows a magnetically reactive OLEDmicrocapsule 10 for forming a capacitor OLED microcapsule 10 with themagnetic aligning field turned on with uncured electrolyte mixture. FIG.30 shows a magnetically reactive OLED microcapsule 10 for forming acapacitor OLED microcapsule 10 with the magnetic aligning field turnedon with cured electrolyte mixture. In accordance with this compositionof the OLED microcapsule, the internal phase comprises OLED material anda magnetically reactive material disposed within a first shell. Anelectrolyte and a curable fluid material surround the first shell. Asecond shell encapsulates the first shell, the electrolyte and thecurable material. In response to an applied magnetic field, the positionof the first shell is changeable relative to the second shell. Uponcuring the curable material, the position of the first shell relative tothe second shell is locked in place. This microcapsule 10 structure canbe used to form capacitors/OLED microcapsules 10 which may beparticularly effective for use in passive matrix displays. Typically, apassive matrix display is driven with a relatively high driving energyso that the emission of light by a driven pixel is intense. Thisintensity overcomes the short driving time of the pixel (as comparedwith the more controllable active matrix backplane). This passive matrixdriving scheme results in shorter display life, higher power consumptionand lower display quality. When a charging voltage is applied (such asduring a charging scan of a passive matrix OLED display grid), thecapacitor elements of the microcapsule 10 store applied electricalenergy. The charging voltage can be controllably applied to selectedpixels and in multiple scans to vary the stored charge in themicrocapsules 10 associated with each pixel. When a trigger voltage isapplied (during the display writing scan), the OLED material emits lightin response to the trigger voltage and in a manner dependent on thestored charge. With the proper selection of microcapsule 10 materials,an RC circuit is formed giving the OLED pixel an increased and morecontrolled light emission time and intensity.

FIG. 31 shows a pixel comprised of a chain of capacitor OLED beingcharged by a charging voltage. FIG. 32 shows a pixel comprised of achain of capacitor OLED being triggered for light emission by a triggervoltage. The microcapsules 10 act as capacitor elements that are chargedup with a charging voltage. A trigger voltage is then applied when theOLED pixel is to emit light.

FIG. 33 shows OLED microcapsules 10 randomly dispersed within a fluidbut hardenable carrier fluid 12. A first electrode 14 and a secondelectrode 14 are provided defining a gap there between. Within the gap,field reactive OLED particulate is randomly dispersed within a fluidcarrier 12. The electrodes 14 can be preformed on a substrate, such asglass. Alternatively, one or both grids of electrodes 14 can bepreformed on a flexible carrier 12 enabling roll-to-roll manufacturing.

FIG. 34 shows OLED microcapsule chains aligned within an appliedaligning field formed within unhardened carrier fluid 12. Uponapplication of an aligning field, the OLED field-reactive materialorient along the field lines and form chains within the still-fluidcarrier 12 (analogous to electro rheological fluid mechanics).

FIG. 35 shows OLED microcapsule chains aligned within an appliedaligning field held in alignment within hardened carrier 12. With thealigning field still applied, the carrier 12 is cured (for example,using light or heat) to form a solid phase to lock the chains of OLEDfield-reactive material into position. With the proper selection ofcarrier 12 material, the OLEDs can be energized to create the curinglight to simplify the fabrication process. Alternatively, a light source28 such as a laser or other light emitter, can be used to controllablyapply the curing light.

FIG. 36 shows the OLED microcapsule 10 structure shown in FIG. 35 with adrive voltage applied and light being emitted from the OLED microcapsulechains. When a voltage is applied to the electrodes 14, the OLED chainenables hole and electron movement, raising the energy state of the OLEDmaterial and generating light.

FIG. 37 illustrates a method for forming an OLED particulate having ahole transport layer and an electron transport layer. Hole transportmaterial and electron transport material are combined to form stableparticles. FIG. 37 illustrates the formation of an OLED particle. Holetransport material having a net positive charge and electron transportmaterial having a net negative charge are mixed together in a liquid sothat the opposing polarities of the particles creates an attractiveforce resulting in electrically stable particles. The OLED particulateis formed by providing a first particle, comprised of a hole transportmaterial that has a net positive electrical charge. A second particle isprovided comprised of an electron transport material having a netnegative electrical charge. The hole transport particle and the electrontransport particle are brought together in a liquid and combined to forma unified OLED particulate having a hole transport layer and an electrontransport layer forming a heterojunction between them.

FIG. 38 illustrates a method for forming an encapsulated OLEDparticulate. The hole transport material and the electron transportmaterial can be combined into a single particle by ejecting theconstituent particles towards each other. The positive and negativecharges will attract to form an electrically neutral dielectricparticle. This particle may be coated with an encapsulating shell orleft uncoated.

FIGS. 39-41 show the steps for forming a multi-layered OLED particle. Inthis case, as shown in FIG. 39, individual particles of electrontransport material are imparted with a net negative electrical charge bya charge source 34 and ejected from a nozzle 36. Particles of a blockingmaterial are imparted with a net positive charge and ejected from asecond nozzle 36 towards the stream of electron transport materialparticles. Field applying electrodes 38 may be provided for directingthe respective charged particles so that they combine together to forman electrically neutral dual layer particle. The field applyingelectrodes 38 may also be useful for attracting and removing from thecombined particle stream the charged particles that do not combine inthe dual layer particle. In a similar manner, a dual layer holetransport and photo active layer particles can be ejected with inducedcharges and directed to combine into a dual layer particle containingthe hole transport material and the photo active material. As shown inFIG. 41, the two dual layer particles are imparted with oppositeelectrical charge and ejected from nozzle 36 towards each other wherethey combine to form the completed multi layered OLED particulate. Theamount of charged induced in the particles can be controlled to adjustthe alignment of attracted constituents.

The OLED particulate comprises organic-layered particles, which includea hole transport layer and an electron emitter layer. A heterojunctionis formed at the interface between the hole transport layer and theelectron emitter layer. Each organic-layered particle may also include ablocking layer adjacent to the electron emitter layer and an emissivelayer adjacent to the hole transport layer, thereby forming a stackedorganic layered structure. The blocking layer is provided forfacilitating the proper flow of electrons and hole, and the emissivelayer is provided for facilitating the emission of photons when theenergy state of the OLED particulate is raised.

FIG. 40 illustrates a second step in forming a multi-layered OLEDparticulate. The amount of charge induced in particles can be controlledto adjust alignment of attracted constituents. FIG. 41 illustrates athird step in forming a multi-layered OLED particulate. Relatively weakattractive field keeps layered particles properly aligned, withoutcausing attachment of particles to electrodes 14. The relatively morenegatively attractive ETL side attracted to a positive attractive force.More positive towards one end, with an overall net positive charge onHTL/EML layered particle and more negative towards another end, with anoverall net negative charge on ETL/BL layered particle. With the properselection of constituent materials, the electrical properties of the HTLand ETL material should be effective to cause the larger degree ofinduced charge to occur at the those ends of the layered particles.

The OLED particulate may comprise a dielectric OLED microcapsule. TheOLED particulate is formed by the steps of first providing a firstparticle comprised of a hole transport material. The hole transportmaterial has a net first electrical charge. A second particle comprisedof an electron transport material is provided having a net secondelectrical charge. The first electrical charge is of opposite polarityfrom the second electrical charge. The first particle and the secondparticle are brought together to form a unified OLED particulate havinga hole transport layer and an electron transport layer forming ahetero-junction between them. The first particle may further include aphoton-active layer. This photon-active layer may be a light emissivelayer in which case the OLED forms a light emitting device, or a lightreceptive layer, in which case the OLED forms a light-detecting device.

FIG. 42 schematically shows a full-color OLED display, constructed inaccordance with the present invention, having a dichromatic displaylayer for improving the display contrast, power efficiency and forproviding display viewing in bright sunlight. The dichromatic displaylayer may be formed, for example, using a conventional LCD pixilatedlight modulator layer. Further, the dichromatic display layer can becomprised of dichromatic microcapsules that can be oriented to reflector absorb impinging light using an aligning field. The dichromaticmicrocapsules 40 can be oriented using an applied electrical field. Inthis case, the dichromatic microcapsules 40 are electrically reactive.Alternatively, in accordance with the present invention, the dichromaticmicrocapsules may be magnetically reactive. In this case, themicrocapsule can be constructed having a north magnetic pole and a southmagnetic pole, each pole being associated with a respective color of abi-color microcapsule. A construction similar to the capacitor/OLEDmicrocapsule shown in FIGS. 28-32 can be used to create microcapsulesthat can be controllably oriented in an applied magnetic field. Thedichromatic display layer provides a light reflective display for use inbright sunlight and other appropriate ambient light conditions, as wellas other display enhancing effects. The dichromatic pixel layer can beformed adjacent to the last subsequent OLED pixel layer. Thisdichromatic pixel layer results in a display that can viewed in directbright sunlight as well as with improved contrast in indoor ambientlighting conditions. Further, additional subsequent OLED pixel layerscan be provided which emit light in additional color range having acolor and/or light intensity different from the color and/or lightintensity of the other OLED pixel layers.

To control the reflection of the emitted light from the OLED RGB pixelsin automatic mode the OLED brightness and the reflection/absorptiondichromatic microcapsule 40 is automatically controlled to optimizepower consumption and display quality. Photodetection elements are usedto determine that level of ambient light and adjust thereflection/absorption/image displaying capabilities of the inventivedisplay. Further, the inventive OLED device can be configured so as todetect light impinging on a pixel grid formed in accordance with thepresent invention. In this case, the OLED particulate of a first OLEDpixel layer emits electrical energy in response to the reception ofphotons and applies the electrical energy as a detectable signal to thefirst and second layer electrodes 14. Further, a black and white and/orfull color CCD-type camera can be formed, by tuning the wavelength rangeat which subsequent layers of OLED pixels are photo reactive.Photodetectors are used to determine when to use dichromatic displayelements. If the dichromatic pixels (e.g., dichromatic microcapsules 40)are turned to the reflection side, OLED emission will be reflected andmore light emitted from the display. If turned to the absorption side,better display contrast may be obtained. If the OLED layers are turnedoff, the dichromatic pixels become a reflective (or two color) displayfor use in bright light or energy saving conditions. This driving schemerequires very low power—only have to apply power to the pixels to changeorientation, then the state remains until power is applied again. Forapplications such as cell phones, the ability to see a display in brightlight is an important consideration. When the phone is in brightsunlight, the dichromatic display elements are used and the OLEDs areoff and transparent (the display is reflective and monochrome (e.g., ablack and white display)). When the phone is indoors or in lower ambientlight, the emissive pixels are used (full color display). As examples ofhow the dichromatic display layer improves the inventive display, undernormal ambient light (indoor, office lighting) the dichromaticmicrocapsules 40 can be oriented to absorb the reflection of ambientlight to improve the contrast of the display.

In low ambient light (airplane, car, dusk) the dichromatic displayelements can be turned oriented to reflect the OLED emission so that theOLED display elements can be driven with lower energy consumption. Thedichromatic display elements can be automatically oriented andcontrolled to provide power savings and improve contrast. Light filtersand side/side pixels can be mixed with the display stack to create avariety of display options. Further, IR and other emitters and detectorscan also be included to create “invisible” maps that can only be readwith night vision aides. Other display possibilities include windshieldsthat automatically block out high light sources like the sun andoncoming high beams; and goggles that enhance vision, provide nightvision, and include telescopic and stereoscopic capabilities.

FIG. 43 schematically shows the full-color OLED display shown in FIG.42, with the dichromatic pixels oriented for reflecting emitted OLEDlight. When the dichromatic picture elements are reflective (oriented sothat the reflective side of the sphere is facing toward the emissiveside of the display), then the light emitted from the OLED elements isreflected for use in forming the display image. The orientation of thedichromatic picture elements can be automatically controlled dependingon the ambient light detected by a photodetector.

FIG. 44 schematically shows the full-color OLED display shown in FIG.42, showing the relative strength of reflected light depending on thedichromatic pixel orientations. The orientation of each respective pixelstack's dichromatic pixel element, determines the contrast, ambient andemitted light reflectivity.

FIG. 45 shows magnetically-active OLED microcapsules 10 randomlydispersed within a fluid but hardenable carrier fluid 12 along withdesiccant particulate. The carrier fluid 12 can include a conductiveelement, carbon or powdered iron for example. The carrier fluid 12should be selected to have the appropriate electrical properties so thatthe path of least electrical resistance in the completed display deviceis through the OLED material, and not through the carrier 12.Accordingly, the carrier fluid 12 may have a semi-conductivecomposition. Desiccant particles 42 are included within the carrierfluid 12 to improve protection against contamination. The desiccant canbe for example, a finely powdered silica based particulate. Thisdesiccant can be included in the shell and/or the internal phase of theOLAM microcapsules, depending on the microcapsule composition.

FIG. 46 shows the magnetically-active OLED microcapsule chains alignedwithin an applied magnetic aligning field within the unhardened carrierfluid 12. The applied magnetic field can be obtained by permanentmagnets brought into position relative to the display electrodes, orelectromagnets that are controlled to apply the magnetic field as neededto cause the desired microcapsule alignment and orientation.

FIG. 47 shows the magnetically-active OLED microcapsule chains alignedwithin the applied magnetic aligning field held in position within thehardened carrier 12. The carrier fluid 12 can include a conductiveelement—carbon, for example. Desiccant particles 42 are included withinthe carrier fluid 12 to improve protection against contamination.

FIG. 48 shows the magnetically-active OLED microcapsule 10 structurewith light being emitted from the OLED microcapsule chains in responseto a driving applied to the electrodes. FIG. 49 schematicallyillustrates a full color OLED display having high intensity visiblelight display layers and an infrared display layer.

FIG. 50 shows an OLED display layer and a liquid crystal lightmodulating layer 44. The liquid crystal display layer 44 can be used asthe dichromatic display layer described above. The liquid crystal lightmodulating layer 44 can also provide the inventive display with thecapability of being selectively reflective. With this capability, thelight-blocking windshield described with regard to FIGS. 57 and 58 isobtained. Further, a window can be formed that is transparent whenneeded, can be switched to being an emissive display (viewable from bothor only one side), is selectively light blocking, and can be a bi-coloror reflective display.

FIG. 51 shows an inventive OLED display fabricated with thin films oforganic material with photodetection elements. Photodetector elementscan be incorporated into each pixel stack, or disposed in a differentresolution grid. The ambient light, whether sunlight or firelight,received by the photodetectors is used to control the opticalcharacteristics of the OLED pixels associated with each photodetector.This construction can be used with microcapsule-based fabrication or anyother display constructions. This enables features such as windshieldsthat block out (using, for example, LCD shutters) high light sources,such as bright sunshine, overhead streetlights, or headlights beamingfrom another car. OLED solar cell components or pixel layers can be usedto “recycle” the energy emitted by the OLED emitters. Some of theemitted light energy impinges on the solar cells and generate light.This, along with the inventions described herein and the sheet batterydescribed in the above-referenced co-owned Patent Applicant entitled“Printer and Method for Manufacturing Electronic Circuits and Displays”,can enable lightweight, relatively inexpensive, dichromatic newspapers(as described herein in FIG. 1) that recharge in sunlight (or evenindoor ambient light) to enable full-color emissive video or stillimages.

FIG. 52 shows an OLED microcapsule 10 wherein the shell is slightly lessconductive than the encapsulated OLED material. The shell is slightlymore resistive than the OLED material so that current does not flowaround shell, but instead flows through OLED material. The particulatecan be organic or inorganic, with chips of LED material combined andoriented, as necessary, with other materials as is described herein withregard to OLAM materials.

FIG. 53 shows an OLED microcapsule 10 wherein the OLED material isencapsulated along with an electrolyte. A hole transport materialcomprises the shell, and a shell around MAG is insulative to keep themagnetic material from having unwanted influence of the electricalbehavior of microcapsule. OLED material is contained within theelectrolyte solution, the electron carriers in the electrolyte can becontrolled depending on the needed specification of the microcapsules10. For example, the microcapsules 10 charge-carrying requirements ofthe electrolyte can be tailored to match the electrical flow for aparticular OLED constituent material. Thus, microcapsules 10 can beformulated based on the empirically or otherwise determinedcharacteristics of a particular formula, or even a particular batch, ofOLAM. Other additional material can be included in the internal phase orthe shell of the microcapsule, or added to the carrier material, orincluded as other microcapsules 10 within the carrier 12. For example, aphosphorescent OLED microcapsule 10 may require different light-inducingapplied electrical energy. Light of a particular wavelength, for exampleinfrared, can trigger the OLED emission at other wavelengths. In thiscase, OLAM, or other material such an inorganic semiconductor, isincluded to generate electricity in response to IR light. The generatedelectricity is used to cause an emission of other wavelengths of lightby the OLED pixel layers. This capability makes possible a map, forexample, that can be read with an infrared flashlight (keeping thestealth advantage, while avoiding the need for the map reader to havenight vision, as is the case when the map is the IR emitter).

FIG. 54 shows an OLED microcapsule 10 wherein the OLED material and thehole transport material are contained in solution within a conductiveshell. This construction may be driven with AC or DC current. The OLEDparticulate is formed, by microencapsulating an internal phase within ashell. The internal phase or the shell includes an OLED material andeither the internal phase or the shell includes a field reactivematerial. The field reactive material comprises either or both anelectrostatic and a magnetically reactive material. In accordance withanother composition of the inventive microcapsule, the internal phasecomprises an OLED emitter material and an OLED hole transport materialdispersed in solution. Color dyes may also be included within theinternal phase. The solvent may be a fluid organic solvent. In order toprovide the alignment capabilities of the microcapsules 10, either theinternal phase or the shell may include a field reactive component.

FIG. 55 shows the OLED microcapsules 10 shown in FIG. 54 including amagnetically active material. The magnetic material is included as aseparate microcapsule 10 with an electrically insulative shell containedwithin the internal phase of a second conductive shell that alsoencapsulates a solution of the OLED material (electron transportmaterial and hole transport material). The electrically insulatedmagnetic material enables microcapsule 10 alignment within a magneticfield, without it becoming an electrical short within the microcapsule.The OLED microcapsules 10 can have constituent parts including at leastone of hole transport material, electron transport material, fieldreactive material, solvent material, color material, shell formingmaterial, barrier material, desiccant material, colorant material, lightcurable, heat expandable, heat contracting, heat curable and heatmeltable material. The constituent parts of the microcapsule 10 form atleast one internal phase and at least one shell. The constituent partsare selected so as to have electrical characteristics that result in apreferred path of electrical conduction (or electron and hole mobility)through the hole transport material and the electron transport material.By this construction, the microcapsule 10 behaves as a pn junction uponapplication of an electrical potential to the first electrode 14 and thesecond electrode 14.

FIG. 56 illustrates the OLED microcapsule 10 shown in FIG. 54 used forcreating a general lighting or display back lighting OLED device. Forgeneral lighting purposes, OLED and hole transport material ismicroencapsulated in solvent form. The microcapsules 10 are randomlydispersed within a conductive carrier 12 material, for example aconductive epoxy mixture. The microcapsules 10 can be disposed betweentwo planer electrodes 14. The “self-healing” capabilities describedherein are used to correct electrical shorts between the planarelectrodes 14.

FIG. 57 illustrates a transparent, flexible OLED display fabricated foruse as part of a vehicle windshield. A liquid crystal (or other)light-modulating grid may also be included. The light-modulating grid isused to provide a shutter for blocking high intensity light source 28,such as the sun and oncoming headlights. Photodetector elements (whichmay be included in grid form within the windshield and/or in anotherarrangement such as an array) detects when a light source 28 is at ahigher intensity than the ambient light. At the location of the detectedhigh intensity light source 28, the light is shuttered (e.g., liquidcrystal within certain pixels is oriented) so that the incoming light isblocked. A radar system, IR camera of other object detecting system canbe used to determine when an object is in the road, such as a deer or adog. If such an object is detected, its image of that object or someindication is produced in the OLED display at the location on thewindshield corresponding to where the object would be viewed by thedriver. Information, such as speed, radio channel, incoming cell callnumber, etc., can be displayed by the OLED display as a heads up displayimage. For an example of a driver circuit for the light shutter, aphotoactive grid generates an electrical potential between twoelectrodes 14. That electrical potential (amplified if necessary) iseffective to cause structures (molecules or crystals or molecularchains) to orient so that light is selectively blocked. This mechanismmay also be used to create a fresnel-type lens system (creating acurvature (focus ability) of a received light image using an essentiallyflat optical element.

FIG. 58 is a block diagram showing the basic components of a driverdisplay system using an OLED display. A controller controls a displaygrid and receives input from a photodetector grid. A display driverdrives the display grid, under the control of the controller, inresponse to the photodetector grid, an IR camera and/or other detectionsystem such as a radar, sonar, ultrasonic, or the like.

FIG. 59 illustrates an OLED light emissive element. The OLED element canbe constructed from sheets of OLED organic material stacks 46, and canbe formed on glass or plastic substrates 24 and cut to size. Theelectrode 14 leads can be fixed to the cut OLED stack 46 and disposedwithin an evacuated or inert gas filled bulb. The bulb can be solid andtransparent or light diffusive, forming a robust, solid state, lightbulb for flashlights or other applications where a conventional LED mayotherwise be employed.

FIG. 60 shows the OLED light emissive element having a conventionallight bulb form factor. OLED light can be fabricated into the same formfactor as a conventional light bulb so that it can be easily installedinto existing light sockets. The orientation of the organic stack 46,reflective anode and transparent anode enables the light to be projectedoutward from the bulb. An array of devices can be configured so that thelight is emitted in an omni-directional or directional manner. The OLEDelement can be constructed from sheets of OLED light stacks 46, and canbe formed on glass or plastic substrates 24 and cut to size. Theelectrode 14 leads can be fixed to the cut light stack and disposedwithin an evacuated or inert gas filled bulb. The threaded portion ofthe bulb can include an ac to dc converting circuit so that theconventional sockets, lampshades, etc., already in the home or officeare still usable. Alternatively, another form factor, such as holidaylighting, rope lighting, etc., can be used. The cut OLED light stack canbe shaped as desired, square, long and thin, etc. Also, the same basicstructure can be used to make OLED light in a conventional LED package.

FIG. 61 illustrates an OLED device fabricated using light emissivelayers and light detecting layers. The OLED display device can includelayers of light emission pixels and layers of light detection pixels.The light detection pixels can be used to detect ambient light andcontrol the intensity of the light emission pixels. As with some of theother device constructions described herein, the formation of the OLEDpixel layers can be done using the inventive microcapsule 10 fabricationmethod and/or a combination with other fabrication methods such asinkjet, spin coating, vacuum deposition, evaporation, etc. for formingan OLED organic stack 46.

FIG. 62 illustrates stereoscopic goggles having OLED display deviceelements 48. The photodetection pixels can be formed so as to effect acamera incorporated within the OLED display device elements 48. Thecamera optics can include lenses that change shape and/or focal pointdepending on whether the image is focusing on the human eye or thecamera pixel elements. Alternatively, or in addition, CCD-type cameras50 can be provided adjacent to the OLED display device elements 48.

FIG. 63 illustrates a flexible OLED display having a curvature thatcompensates for the human eye's range of motion. The image displayed onthe curved wraparound OLED display is refreshed so that the eye movementas well as the head movement of the user is accounted for. With thisstereoscopic vision aide, the user's head movement can be determined byaccelerometers and gyroscopic circuits. The eye movement is determinedby reflecting IR (or some wavelength depending on the ambient light) offthe retina and detecting the reflection by photodetectors which may beincorporated in the OLED display.

FIG. 64 illustrates a flexible OLED display having microlens elements 52for focusing emitted light at the appropriate physical location within ahuman eye. An optical lens can be used to focus light onto CCD-typeelements to create microlens elements 52 that focus the pixel lightsource 54 at the focus spot in the human eye. The optical properties ofthe microlens element 52 can compensate for vision problems.

FIG. 65 illustrates a wraparound visor 56 having a curved, flexible OLEDdisplay and speakers 58. The inventive stereoscopic vision aid has ahigh resolution OLED display. The OLED display is shaped so that fieldof vision is as full as practical.

FIG. 66 illustrates a wall 60 of a house having an inventive OLEDdisplay window 62, the window 62 being driven so as to be transparentwith trees 64 outside the house visible through the window 62. Theinventive window 62 can be constructed along the lines of the OLEDdisplays described herein. As will all of the applications for theinventive OLED technology, the various elements comprising the variousversions of the invention described herein can be mixed and matcheddepending on the intended use for a particular OLED display. Thus, inthis case, the inventive window 62 can be driven so that is transparentwhen needed, can be switched to being an emissive display (viewable fromboth or only one side), is selectively light blocking, and can be a fullcolor, multi-color, monochrome or reflective display.

FIG. 67 illustrates the wall 60 of a house having the inventive OLEDdisplay window 62, the window 62 being driven so as to display multiplesimultaneous video streams 66 including videophone communication,Internet web page and a television program. Multiple streams of displayinformation 66 can be simultaneously received and displayed. Forexample, broadcast video content such as a television program may beshown at a first portion of the display, personalized video content,such as a videophone conversation may be shown at a second portion and aweb page, including mapped hyperlink content, may be shown at a thirdportion. With an LCD light modulating layer, the content displayed onthe inventive OLED display window 62 can be viewable from outside thehouse (from poolside, for example), or LCD light modulating layer can becontrolled so that the emitted display light can be blocked from viewfrom outside the house.

FIG. 68 illustrates the wall 60 of a house having the inventive OLEDdisplay window 62, the window being driven so as to be a mirror. In thiscase, the LCD light modulating layer can be controlled to block lightfrom being transmitted through the window. Further, as shown in FIG. 57,relatively high intensity light (such as from sun beaming onto thewindow) can be selectively blocked to prevent glare within the house andto keep the house cooler in the summer.

FIG. 69 illustrates an embodiment of the inventive light active deviceshowing a semiconductor particulate randomly dispersed within aconductive carrier. A light active device includes a semiconductorparticulate dispersed within a carrier material. The carrier materialmay be conductive, insulative or semiconductive and allows charges tomove through it to the semiconductor particulate. The charges ofopposite polarity moving into the semiconductive material combine toform charge carrier pairs. The charge carrier pairs decay with theemission of photons, so that light radiation is emitted from thesemiconductor material. Alternatively, the semiconductor material andother components of the inventive light active device may be selected sothat light received in the semiconductor particulate generates a flow ofelectrons. In this case, the light active device acts as a light sensor.

A first contact layer or first electrode is provided so that onapplication of an electric field charge carriers having a polarity areinjected into the semiconductor particulate through the conductivecarrier material. A second contact layer or second electrode is providedso that on application of the electric field to the second contact layercharge carriers having an opposite polarity are injected into thesemiconductor particulate through the conductive carrier material. Toform a display device, the first contact layer and the second contactlayer can be arranged to form an array of pixel electrodes. Each pixelincludes a portion of the semiconductor particulate dispersed within theconductive carrier material. Each pixel is selectively addressable byapplying a driving voltage to the appropriate first contact electrodeand the second contact electrode.

The semiconductor particulate comprises at least one of an organic andan inorganic semiconductor. The semiconductor particulate can be, forexample, a doped inorganic particle, such as the emissive component of aconventional LED. The semiconductor particulate can be, for anotherexample, an organic light emitting diode particle. The semiconductorparticulate may also comprise a combination of organic and inorganicmaterials to impart characteristics such as voltage control emission,aligning field attractiveness, emission color, emission efficiency, andthe like.

The electrodes can be made from any suitable conductive materialincluding electrode materials that may be metals, degeneratesemiconductors, and conducting polymers. Examples of such materialsinclude a wide variety of conducting materials including, but notlimited to, indium-tin-oxide (“ITO”), metals such as gold, aluminum,calcium, silver, copper, indium and magnesium, alloys such asmagnesium-silver, conducting fibers such as carbon fibers, andhighly-conducting organic polymers such as highly-conducting dopedpolyaniline, highly-conducting doped polypyrrole, or polyaniline salt(such as PAN-CSA) or other pyridyl nitrogen-containing polymer, such aspolypyridylvinylene. Other examples may include materials that wouldallow the devices to be constructed as hybrid devices through the use ofsemiconductive materials, such as n-doped silicon, n-doped polyacetyleneor n-doped polyparaphenylene.

As shown in FIG. 70, an embodiment of the inventive light active devicemay have the semiconductor particulate aligned between electrodes. Theemissive particulate act as point light sources within the carriermaterial when holes and electrons are injected and recombine formingexcitons. The excitons decay with the emission of radiation, such aslight energy. In accordance with the present invention, the emissiveparticulate can be automatically aligned so that a significant majorityof the point light sources are properly oriented and disposed betweenthe electrodes (or array of electrodes in a display). This maximizes thelight output from the device, greatly reduces cross-talk between pixels,and creates a protected emissive structure within the water, oxygen andcontamination boundary provided by the cured carrier material.

In this case, the mixture disposed within the gap between the top andbottom electrodes includes a field reactive OLED particulate that israndomly dispersed within a fluid carrier. An aligning field is appliedbetween the top electrode and the bottom electrode. The field reactiveOLED particulate move within the carrier material under the influence ofthe aligning field. Depending on the particulate composition, carriermaterial and aligning field, the OLED particulate forms chains betweenthe electrodes (similar to the particulate in an electrical or magneticrheological fluid in an electric or magnetic field), or otherwisebecomes oriented in the aligning field. The aligning field is applied toform a desired orientation of the field reactive OLED particulate withinthe fluid carrier. The fluid carrier comprises a hardenable material. Itcan be organic or inorganic. While the desired orientation of the fieldreactive OLED particulate is maintained by the aligning field, thecarrier is cured to form a hardened support structure within which islocked in position the aligned OLED particulate.

FIG. 71 illustrates an embodiment of the inventive light active deviceshowing semiconductor particulate and other performance enhancingparticulate randomly dispersed within the conductive carrier material.The semiconductor particulate may comprise an organic light activeparticulate that includes at least one conjugated polymer. Theconjugated polymers having a sufficiently low concentration of extrinsiccharge carriers. An electric field applied between the first and secondcontact layers causes holes and electrons to be injected into thesemiconductor particulate through the conductive carrier material. Forexample, the second contact layer becomes positive relative to the firstcontact layer and charge carriers of opposite polarity are injected intothe semiconductor particulate. The opposite polarity charge carrierscombine to form in the conjugated polymer charge carrier pairs orexcitons which emit radiation in the form of light energy.

Depending on the desired mechanical, chemical, electrical and opticalcharactistics of the light active device, the conductive carriermaterial can be a binder material with one or more characteristiccontrolling additives. For example, the binder material may be across-linkable monomer, or an expoxy, or other material into which thesemiconductor particulate can be dispersed. The characteristiccontrolling additives may be in a particulate and/or a fluid statewithin the binder. The characteristic controlling additives may include,for example, a desiccant; a conductive phase, a semiconductive phase, aninsulative phase, a mechanical strength enhancing phase, an adhesiveenhancing phase, a hole injecting material, an electron injectingmaterial, a low work metal, a blocking material, and an emissionenhancing material. A particulate, such an an ITO particulate, or aconductive metal, semiconductor, doped inorganic, doped organic,conjugated polymer, or the like can be added to control the conductivityand other electrical, mechanical and optical characteristics. Colorabsorbing dyes can be included to control the output color from thedevice. Florescent and phosphorescent components can be incorporated.Reflective material or diffusive material can be included to enhance theabsorption of received light (in the case, for example, of a display orphotodetector) or enhance the emitted light qualities. In the case of asolor collector, the random dispersal orientation of the particulate maybe preferred because it will enable a solar cell to have light receivingparticulate that are randomly oriented and the cell can receive lightfrom the sun efficiently as it passes over head. The orientation of theparticulate may also be controlled in a solar cell to provide a bias forpreferred direction of capture light.

The characteristic controlling additives may also include materials thatact as heat sinks to improve the thermal stability of the OLEDmaterials. The low work metal additives can be used so that moreefficient materials can be used as the electrodes. The characteristiccontrolling additives can also be used to improve the mobility of thecarriers in the organic materials and help improve the light efficiencyof the light emitting device.

FIG. 72 illustrates an embodiment of the inventive light active deviceshowing different species of organic light active particulate dispersedwithin a carrier material. The turn-on voltage for each species can bedifferent in polarity and/or magnitude. Emissions of differentwavelengths or colors can be obtained from a single layer of the mixtureof the organic light active particulate and carrier material. The color,duration and intensity of the emission is thus dependent on thecontrolled application of an electric field to the electrodes. Thisstructure has significant advantages over other full color or multicolorlight devices, and can also be configured as a wide spectrumphotodetector for applications such as cameras. The organic light activeparticulate can include organic and inorganic particle constituentsincluding at least one of hole transport material, organic emitters,electron transport material, magnetic and electrostatic material,insulators, semiconductors, conductors, and the like. As is describedherein, a multi-layered organic light active particulate can be formedso that its optical, chemical, mechanical and electrical properties arecontrolled by the various particle constituents.

FIG. 73 illustrates an organic light active particle formed from apolymer blend and FIG. 74 illustrates the polymer blend organic lightactive particulate dispersed within a conductive carrier. The organiclight active particulate may includes particles comprised from a polymerblend, including at least one organic emitter blended with at least oneof a hole transport material, an electron transport material and ablocking material. FIG. 75 illustrates the polymer blend organic lightactive particle showing light active sites. Upon the application ofelectrical field to the electrodes, sites within the polymer blendparticle will act as point sources of light emissions. These lightactive sights are located where the appropriate constituents of thepolymer blend meet so that electrons and holes injected into thesemiconductor material combine into excitons and decay with the releaseof photons. The organic light active particulate may includemicrocapsules having a polymer shell encapsulating an internal phase.The internal phase and/or the shell can be comprised of the polymerblend including an organic emitter blended with at least one of a holetransport material, an electron transport material and a blockingmaterial.

Nanoparticles are used in applications, such as drug deliver devices.Others have shown that very small polymer-based particles can be made bya variety of methods. These nanoparticles vary in size from 10 to 1000nm. A drug can be dissolved, entrapped, encapsulated or attached to ananoparticle matrix. Depending on the method of preparation,nanparticles, nanospheres or nanocapsules can be obtianed. (see,Biodegradable Polymeric Nanoparticles as Drug Delivery Devices, K. S.,Soppimath et al., Journal of Controlled Release, 70(2001) 1-20,incorporated by reference herein). In accordance with the presentinvention, an OLED particulate can be formed having a very smallparticle size. The small particle size offers a number of advantages.For example, the ultimate resolution available of a display may bedependent on the size limitation of the OLED particles. Thus OLEDnanoparticles utilized in accordance with the inventive fabricationmethods will enable extremely high resolution display devices. Also, thevery small OLED particle size will enable more light point sourceswithin a given volume, such as the volume making up a display pixel. Alarge number of light point sources can result in more uniform pixelcharacteristics, longer device lifetimes and more efficient powerconsumption. In accordance with the present invention, various methodscan be employed to form the OLED nanoparticles. The various methodsdisclosed in this reference for the formation of drug deliverynanoparticles can be adapted for the formation of OLED nanoparticles.These methods include the solvent evaporation method, spontaneousemulsification solvent diffusion method, saltingout/emulsification-diffusion method, production of OLED nanoparticlesusing supercritical fluid technology, the polymerization of monomers,and nanoparticles prepared from hydophilic polymers.

FIG. 76 illustrates a polymer blend organic light active particulatehaving a field attractive constituent for aligning the particle in analigning field. In this case, the particulate includes a field reactivematerial, such as a magnetically reactive speck. The magneticallyreactive speck can be included in the particulate through an appropriateencapsulation, mixing, blending or coating technique.

FIG. 77 illustrates composite microcapsules containing multilayeredorganic light active particles, each having a different light wavelengthemission and turn-on voltage.

The composite microcapsules or different species of particulate can beused to form a single layer voltage controlled light active device foremitting two or more colors of light. Instead of needing a separate setof electrodes and a separate layer of the semiconductor and carriermaterial mixture, the present invention enables a single layered devicewith a single pair of electrodes to controllably emit two or more colorsof light.

FIG. 78 illustrates another composite microcapsule containingmultilayered organic light active particles, at least one having a fieldattractive constituent. The field attractive constituent may be requiredto enable alignment of the particles between the driving electrodes.When an aligning field is applied, the field reactive OLED particulatemove within the carrier material under the influence of the aligningfield. The aligning field is applied to form a desired orientation ofthe field reactive OLED particulate within the fluid carrier.

FIG. 79 illustrates three light emitting microcapsule species, eachspecies having a turn-on voltage controlled by the internal phasecomposition and the encapsulating shell composition. The shell may beformed of a polymer have a conductivity based on thickness and/orcomposition so that the specific turn-on voltage of the encapsulatedconjugated polymer particulate is of a desired magnitude. By thisadditional turn-on voltage control enabled by the shell/internal phaseelectrical characteristics, the photons emitted by each species ofconjugated polymer in response to an applied voltage can be tailored asrequired. The carrier fluid can be formulated so that it is more of aninsulator prior to curing, and has the proper degree of conductivityafter curing. In this case, the carrier fluid can act, more or less,like the oil in an oil/particulate electrical rheological fluid. Thehigh voltage required to align the particulate between the electrodescan be applied without too much current passing through the particulateand burning them out. Once aligned, the electrical field can be reducedor eliminated as the carrier fluid cures. The carrier fluid can alsohave additives that affect the turn-on voltages of the different emitterspecies so that the appropriate number of photons is emitted from eachpoint light source for each applied turn-on voltage.

FIG. 80 illustrates an embodiment of the inventive voltage controlledlight active device showing the composite microcapsule particulaterandomly dispersed within a carrier. The internal phase may be a polymerblend containing two or more conjugated polymers, each with a specificturn-on voltage for the controlled emission of color light. In anembodiment of a voltage controlled multi-colored light emitting device,a first electrode is provided with a second electrode disposed adjacentto it and defining a gap therebetween. A mixture of an organic lightactive particulate and a conductive carrier material is disposed withinsaid gap. The organic light active particulate is comprised of firstemitting particles including a first electroluminescent conjugatedpolymer. The first emitting particles emit a number of photons of afirst color in response to a first turn-on voltage applied to theelectrodes. The first emitting particles also a different number ofphotons, zero or more, of the first color in response to other turn-onvoltages. The organic light active particulate further comprises secondemitting particles including a second conjugated polymer. The secondemitting particles emit a number of photons of a second color inresponse to a second turn-on voltage and a different number of photonsof the second color in response to other turn-on voltages. Thus, in thecase of a multi-colored diode or display, different colors areperceivable by the human eye depending on the applied turn-on voltage.The organic light active layer may also include third emitting particlesincluding a third electroluminescent conjugated polymer. The thirdemitting particles emit a number of photons of a third color and/orintensity in response to a third turn-on voltage applied to theelectrodes and a different number of photons of the third color and/orintensity in response to other turn-on voltages. A full color displaycan be obtained by having the first color red; the second color greenand the third color blue. The composite microcapsule can contain threeOLED particles or microcapsules, or it may be made from a conjugatedpolymers and other material, such as non-conjugated polymers, organiclight active materials, field attractive materials, inorganic lightactive material, etc. Each emitter emits light of a specific colorrange, R, G or B. Each color particle is formulated so that it emitslight when a voltage in a specific voltage range is applied between theelectrodes. A plurality of composite microcapsules are dispersed withina carrier fluid. The carrier fluid may be a hardenable material, such asan epoxy, resin, curable organic or inorganic material, heat or lightcurable monomer, and the like.

FIG. 81 illustrates an embodiment of the inventive voltage controlledlight active device showing the composite microcapsule particulatealigned between electrodes. An aligning field applied between the topelectrode and the bottom electrode causes the field reactive OLEDparticulate to move under the influence of the aligning field. Dependingon the particulate composition, carrier material and aligning field, theOLED particulate forms chains between the electrodes (similar to theparticulate in an electrical or magnetic rheological fluid when anelectrical or magnetic field is applied), or otherwise becomes orientedin the aligning field. The aligning field is applied to form a desiredorientation of the field reactive OLED particulate within the fluidcarrier. The fluid carrier may comprise a hardenable material. While thedesired orientation of the field reactive OLED particulate is maintainedby the aligning field, the carrier is cured to form a hardened supportstructure within which is locked in position the aligned OLEDparticulate.

FIG. 82 illustrates the retinal response of the human eye to wavelengthsof light in the visible spectrum. When light enters the eye, it firstpasses through the cornea at the front of the eye and ultimately reachesthe retina at the back of the eye. The retina is the light-sensingstructure of the eye. The retina includes two types of cells, calledrods and cones. Rods are responsible for vision in low light, and conesresponsible for color vision and detail. There are three types of cones,each type responsive primarily to a specific segment of the visualspectrum. The light received by these rod and cone cells sets offcomplex chemical reactions. The chemical that is formed (activatedrhodopsin) creates electrical impulses in the optic nerve. The braininterprets these electrical impulses in the visual cortex. Thecolor-responsive chemicals in the cones are called cone pigments and arevery similar to the chemicals in the rods. There are three kinds ofcolor-sensitive pigments, red-sensitive pigment, green-sensitive pigmentand blue-sensitive pigment Each cone cell has one of these pigments sothat it is sensitive to that color. The human eye can sense almost anygradation of color when red, green and blue are mixed. Humans are ableto perceive color throughout the visual spectrum because of theresponsiveness of the three types of cones. Red absorbing cones absorbbest at the relatively long wavelengths peaking at 565 nm. Greenabsorbing cones have a peak absorption at 535 nm and blue absorbingcones have a peak absorption at 440 nm. The three types of cones areeach most responsive to different portions (R,G,B) of the visiblespectrum, but the segment of responsiveness overlap. Light of a givenwavelength (color), for example 500 nm (green), stimulates all threetypes of cones, but the green-absorbing cones will be stimulated moststrongly.

Typically, a full color display has side by side RGB pixels andgenerates three simultaneous emissions of RGB colored light, producing amixture of wavelengths of light. Color is perceived by the eye throughthe simultaneous stimulation of the three types of cones by the colorlight mixture. In accordance with the present invention, a color isobtained by driving a multi-color producing light active device with anemission cycle during which the appropriate number of photons ofdifferent colors are produced in successive bursts of light emissions. Apredominance of photons of a color is produced during a burst ofemission in response to the application of a turn-on voltage. Anotherburst of a predominance of photons of another color is produced inresponse to the application of a different turn-on voltage. A fractionof the emission cycle is determined during which each turn-on voltage isapplied so that an appropriate number of photons for each color isproduce for each burst. The eye perceives the desired color by thesuccessive predominate stimulation of each type of cone cell. Color isobtained by the combination of Xd # of photons of Red+Yd # of photons ofGreen+Zd # of photons of Blue. It may turn out experimentally that otherwavelengths of like can be used to stimulate the vision system toperceive variable colors from the burst emission of photons, in whichcase the number and wavelength of the different colors along theemissive spectrum can be employed.

The shell of each particle may be a controlling effect on the turn-onvoltage of the encapsulated OLED. The composition of the encapsulatedOLED controls the color of the light emitted. The shell thickness andcomposition can be controlled so that the turn-on voltage of eachprimary color particulate is distinct from the turn-on voltage of theothers. For example, each RGB particle can have a specific shellstructure selected so that when a high turn-on voltage is applied, theelectrons move too slowly through the lower voltage shell and/orinternal phase to cause complete or partial turn-on (i.e., reducednumber of emitted photons) of the encapsulated emitter.

Each color emitter can be formulated so that it has a differentthreshold turn-on voltage and/or a different threshold turn-on pulsewidth and/or a different threshold turn-on polarity. As an example,since more electrons and holes move at higher voltage potential, thehigher voltage emitter made to have a lower pulse width would emit thesame number of photons as the lower voltage, longer pulse widthemitters. But, even though the voltage threshold for lower voltageemitters is exceeded when the higher voltage emitter is driven, thepulse width of the higher voltage is too short to turn-on the lowervoltage emitter. As an example, the hole and/or electron transportmaterial can be formulated to slow down the progress of the electronsand holes in the lower voltage material so that even though moreelectrons and holes are injected at the higher voltage, are not able tocross through the material and recombine in the lower voltage emitter(the recombination of the holes and electrons results in a photon).

A variable DC/AC voltage/current source applies electrical energy to theelectrodes. In response to the applied energy, light is emitted from theparticulate through the top electrode. In an AC voltage application,each cycle has a predetermined voltage. With each cycle, a predominantcolor of light (for example, R, G, B) is emitted in response to thepredetermined voltage (or no color is emitted). The color emitteddepends on the turn-on voltage of the R, G or B particles. Dual colorparticles or tri color particles (or 4 colors, including IR, forexample) are obtainable by the various known particulate constructiontechniques and those described herein. The AC cycles are fast enoughthat the eye perceives the desired color of the visible spectra. Forexample, rods and cones of the eye are stimulated by the three primarycolors separately but in quick succession so that each frame of a video,for example, is perceived in full color. Because of the very fastturn-on times of the emitting particles, and the AC driving scheme, apassive matrix can be used while still obtaining superior video images.Each individual scan cycle of an electrode pair can have a large numberof AC cycles. With each AC cycle, a particular predominant color isemitted. Thus, in each scan cycle, the eye see separate colored lightbursts but the cones and rods are stimulated in such quick successionthat a mix of the primary colors (or, if preferable other two or morecolors) is perceived by the brain from the optic nerve.

By selecting the appropriate formula of the conductive carrier, it canbe a hole transport vehicle and an electron transport vehicle. Theorganic emitter may not have to be a multilayered particulate, butrather, it may be just particles of pure organic emitter.

Depending on the configuration and composition of the variouscomponents, the inventive voltage controlled light active device can beAC driven, with the first turn-on voltage having a polarity and thesecond turn-on voltage having an opposite polarity. The differentturn-on voltages can be a mix of voltages of different polarities andmagnitudes.

The organic light active layer may also comprise at least one additionalemitting particles containing another electroluminescent conjugatedpolymer. The additional emitting particles emitting a number of photonsin response to a turn-on voltage and a different number of photons inresponse to other turn-on voltages. The photons emitted by theadditional emitting particles can have a color that is within thevisible spectrum. In this case, the additional emitting particles canenhance the visible display capabilities. For example, the intensity ofthe light emitted by one of the primary color emitters may becomediminished because of the emitter service lifetime. Other emittershaving the same color, but different turn-on voltage can be put intoservice to maintain the effectiveness of the total display. The photonsemitted by the emitting particles may also be outside the range of thevisible spectrum. For example, infra-red photons can be controllablyemitted to enable stealth military application of the inventive display.

The voltage controlled organic light active device can be constructed asa display. In this case, the first electrode is part of an x-grid ofelectrodes and the second electrode is part of a y-grid of electrodes.The mixture of the organic light active particulate and the conductivecarrier material in the gap between the first electrode and the secondelectrode make up an emissive component of a pixel of a display device.

As an example of voltage controlled emitter, the first and the secondelectroluminescent conjugated polymers may include a plurality ofmembers selected from the group consisting of polythiophenes,poly(paraphenylenes), and poly(paraphenylene vinylene), at least some ofsaid members having substituents selected from the group ocnsisting ofalkyl, alkoxy, cycloalkyl, cycloalkoxy, flouroalkyl, alkylphenylene, andalkoxyphenylene vinylene.

An organic light active display device includes a substrate with a firstgrid of driving electrodes formed on the substrate. A second grid ofelectrodes is disposed adjacent to the first grid of electrodes anddefining a gap therebetween. A mixture of an organic light activeparticulate and a conductive carrier material is disposed within thegap. The organic light active particulate comprising first particlesincluding a first electroluminescent conjugated polymer having a firstturn-on voltage and second particles including a secondelectroluminescent conjugated polymer having a second turn-on voltagedifferent than the first turn-on voltage. When the first turn-on voltageis applied, a first color is emitted by the first electroluminescentconjugated polymer. Light having a second color is emitted by the secondelectroluminescent conjugated polymer in response to the second turn-onvoltage applied to the first electrode and the second electrode.

FIG. 83 illustrates the inventive primary color burst driving method forproducing a perceived full color image by the rapid and sequentialbursts of primary colored light emission. In accordance with the presentinvention, a method is provided for driving a multi-color light emittingdevice, the multi-color light emitting device capable of emitting two ormore colors in sequence. Each color is emitted in response to arespective different applied turn-on voltage. During an emission cycle,a first turn-on voltage is applied having a duration to the lightemitting device so that a first burst of a predominant number of photonsof a first color are emitted. A second turn-on voltage is then appliedduring the emission cycle having a duration and at least one of amagnitude and a polarity different than a magnitude and polarity of thefirst turn-on voltage. For the second turn-on voltage duration, a secondburst of a predominant number of photons of a second color are emitted.In this way, during the emission cycle the first burst and the secondburst occur in rapid succession. A human eye receiving the first burstand the second burst is stimulated to perceive a color that is differentthan the first color and the second color.

During the emission cycle, a third turn-on voltage can be applied havinga duration and at least one of a magnitude and a polarity different thanthe magnitude and polarity of the other turn-on voltages. A third burstof a predominant number of photons of a third color are emitted. Duringthe emission cycle, the first burst, the second burst and the thirdburst occur in rapid succession and the human eye receiving the burstsis stimulated to perceive a color different than the first color, thesecond color and the third color.

In accordance with the present invention, the first color is in the redportion of the visible spectrum, the second color is in the greenportion of the visible spectrum and the third color is in the blueportion of the visible spectrum. The light emitting device is controlledso that the number of photons of each color emitted during each burst ofthe emission cycle results in a predetermined color within the visiblespectrum being perceivable by the human eye. Even though there is notthe three simultaneous emissions of R,G,B emitted by a typical fullcolor display, in accordance with the present invention the burstemission results in the perception of a predetermined color in thevisible spectrum.

FIG. 84 illustrates the inventive retinex burst driving method forproducing a perceived full color image by the rapid and sequentialbursts of colored light emission. In accordance with another aspect ofthe present invention, the intensity, duration and color emitted by themulti-color light emitting device is adjusted according to a retinexdisplay operation. Edwin Land introduced a theory of color vision basedon center/surround retinex (see, An Alternative Technique for theComputation of the Designator in the Retinex Theory of Color Vision,”Proceedings of the National Academy of Science, Volume 83, pp.3078-3080, 1986). Land disclosed his retinex theory in “Color Vision andThe Natural Image,” Proceedings of the National Academy of Science,Volume 45, pp. 115-129, 1959. These retinex concepts are models forhuman color perception. The earlier retinex concepts involved thecomputations based on when color boundaries were crossed in the lightemitted from an image. Land's retinex concept of human vision has acenter/surround spatial computation with a center having 2-4 arc-minutesin diameter and a surround that is an inverse square function with adiameter of about 200-250 times that of the center. Others have shownthat a digital image can be improved utilizing the phenomenon of retinex(see, U.S. Pat. No. 5,991,456 issued to Rahman et al, the disclosure ofwhich is incorporated by reference herein). The inventors of the U.S.Pat. No. 5,991,456 patent used Land's retinex theory and devised amethod of improving a digital image where the image is initiallyrepresented by digital data indexed to represent positions on a display.The digital data is indicative of an intensity value I.sub.i (x,y) foreach position (x,y) in each i-th spectral band. The intensity value foreach position in each i-th spectral band is adjusted to generate anadjusted intensity value for each position in each i-th spectral band inaccordance with an equation based on the total number of unique spectralbands. A surround function is used to improve some aspect of the digitalimage, e.g., dynamic range compression, color constancy, and lightnessrendition. The adjusted intensity value for each position in each i-thspectral band is filtered with a common function. According to theinventors of the U.S. Pat. No. 5,991,456 patent, an improved digitalimage can then be displayed based on the adjusted intensity value foreach i-th spectral band so-filtered for each position.

FIG. 85 illustrates the inventive adjusted color burst driving methodfor producing a perceived full color image by the rapid and sequentialbursts of adjusted colored light emission. The retinex display operationmay include the steps of providing digital data indexed to representpositions on a display. The digital data is indicative of an intensityfor each position in each spectral band. The intensity of each positionin each spectral band is adjusted to generate an adjusted intensityvalue in accordance with a predetermined mathematical equation. Theadjusted intensity value is filtered for each position with a commonfunction. The turn-on voltages are controlled so that the emission ofphotons of each color is based on the adjusted intensity value for eachfiltered spectral for each position.

FIG. 86 is a flow chart showing the steps of the inventive method forforming a multilayered organic light active material particulate. FIG.87 illustrates a layered organic light active material particulateformed by the commingling of a particle of hole transport material witha particle of emissive layer material. In this example, the first mistcomprises a hole transport material (HT) and carrier, and the secondmist comprises an emission layer material (EL) and carrier. FIG. 88illustrates the inventive method of forming a layered organic lightactive material particulate from a hole transport constituent and anemissive layer constituent. Referring to FIGS. 86-88, a first mixture((HT) and carrier) is formed of a first organic light active componentmaterial and a first carrier fluid (step one). A second mixture ((EL)and carrier) is formed of a second organic light active componentmaterial and a second carrier fluid (step two). A first mist isgenerated of the first mixture in an environment so that a firstparticulate of the first organic light active component material istemporarily suspended in the environment (step three). A second mist ofthe second mixture is generated in the environment so that a secondparticulate of the second organic light active component material istemporarily suspended in the environment (step four). The firstparticulate and the second particulate are allowed to commingle andattract together in the environment to form a first layered organiclight active material particulate ((HT)(EL)) (step six). The layeredorganic light active particulate has a first layer of the first organiclight active component material and a second layer of the second organiclight active component material.

FIG. 89 illustrates a multi-layered organic light active materialparticulate formed by the commingling of a layered particle of holetransport/emissive layer material with a particle of electron transportmaterial. FIG. 90 illustrates the inventive method of forming amulti-layered organic light active material particulate from a holetransport/emissive layer constituent and an electron transportconstituent. An organic light active material particulate can be formedhaving multiple layers. A third mixture is formed of a third organiclight active component material (ET) and a third carrier fluid. A fourthmixture is formed of the first layered organic light active materialparticulate ((HT)(EL)) and a fourth carrier fluid. A mist of the thirdmixture is generated in the environment so that a third particulate ofthe third organic light active component material is temporarilysuspended. A mist of the fourth mixture is generated so that the firstlayered organic light active material particulate is temporarilysuspended in the environment. The third particulate and the firstlayered organic light active material particulate are allowed tocommingle and attract together in the environment to form a secondlayered organic light active material particulate. This second layeredorganic light active material particulate includes the first organiclight active material particulate and the third organic light activecomponent material. Thus the resulting organic light active materialparticulate has a multilayered structure that includes all three of theorganic light active component materials arranged in a desired order((HT)(EL)(ET)).

In accordance with the present invention, a multilayered particulatestructure can be obtained for obtaining electrophosphorescent OLEDparticulate. FIG. 91 illustrates a layered organic light active materialparticulate formed by the commingling of a particle of blocking materialwith a particle of electron transport material. FIG. 92 illustrates theinventive method of forming a layered organic light active materialparticulate from a blocking constituent and an electron transportconstituent. FIG. 93 illustrates a layered organic light active materialparticulate formed by the commingling of a particle of emissive layermaterial with a particle of hole transport material. FIG. 94 illustratesthe inventive method of forming a layered organic light active materialparticulate from an emissive layer constituent and a hole transportconstituent. FIG. 95 illustrates a multi-layered organic light activematerial particulate formed by the commingling of a layered particle ofblocking/electron transport material with a layered particle of emissivelayer/hole transport material. FIG. 96 illustrates the inventive methodof forming a multi-layered organic light active material particulatefrom a blocking/electron transport constituent and a holetransport/emissive layer constituent. As shown in FIGS. 89-96, amulti-layered particle can be built up having the constituent partsordered in a desired manner so that the multi-layered particle is aneffective point source light emitter.

Additional layers can be added to the multilayered structure by forminganother mixture of another organic light active component material andanother carrier fluid and forming yet another mixture of a previouslyformed layered organic light active material particulate and yet anothercarrier fluid. The resulting particles are suspended in the environmentas described above and allowed to commingle and attract together to formthe multilayered particulate structure.

At least one of the first, second and subsequent organic activecomponent material may comprise at least one of a hole transportmaterial, an emission layer material, an electron transport material,and a blocking material. Other organic active component material caninclude at least one of a magnetic material, an electrostatic material,a desiccant, hole injecting material, and an electron injectingmaterial. Thus, a selection of constituents can be made so that amultilayered particulate structure can be formed having desiredelectrical, optical, mechanical, field attractive and chemicalproperties.

FIG. 97 illustrates a layered organic light active material particulateformed by the commingling of a particle of field attractive materialwith a particle of electron transport material. FIG. 98 illustrates theinventive method of forming a layered organic light active materialparticulate from a field attractive constituent and an electrontransport constituent. FIG. 99 illustrates a layered organic lightactive material particulate formed by the commingling of a particle ofemissive layer material with a particle of hole transport material. FIG.100 illustrates the inventive method of forming a layered organic lightactive material particulate from an emissive layer constituent and ahole transport constituent. FIG. 101 illustrates a multi-layered organiclight active material particulate formed by the commingling of a layeredparticle of field attractive/electron transport material With a layeredparticle of emissive layer/hole transport material. FIG. 102 illustratesthe inventive method of forming a multi-layered organic light activematerial particulate from a field attractive/electron transportconstituent and a hole transport/emissive layer constituent. As shown inFIGS. 97-102, the point source light emitting particulate can be fieldattractive by the inclusion of a material, such as a magneticallyreactive material, as one of the constituents of the particulate.

At least one of the first and the second and subsequent carrier fluidsmay be a solvent of the organic light active component material, and thesolvent removed by evaporation or otherwise to leave the particulatesuspended in the environment. Alternatively, a precipitation can beobtained by a suitable chemical reaction depending on the componentmaterial and the solvent. The chemical reaction may be caused by theaddition of material to the solution prior to of after forming the mist.The chemical reaction may be caused by the carrier material of theopposing mist, or the precipitating material may be otherwise appliedwhen the solution is in the mist form.

The first, second and subsequent organic light active component materialmay a fine particulate insoluble in the respective first, second andsubsequent carrier fluids. The third and subsequent organic light activeparticulate may be a multi-layered organic light active materialparticulate, which may be formed by the inventive method,microencapsulation, chemical reaction of two or more constituents,electric or magnetic attraction of two or more constituents, or othermeans for forming a multi-layered organic light active materialparticulate. The organic light active material particulate formed inaccordance with the inventive method may also be encapsulated in a shellto impart chemical, magnetic, electrical or optical attributes to theparticulate. For example, in the case of a voltage controlled emitter,the microcapsule shell can be composed of a material selected to preventunwanted photon emission from the internal phase emitter, and/or topromote wanted photon emission from the emitter, depending on theapplied turn-on voltage.

The environment in which the particulate is formed can be an inert gas,reactive gas, a vacuum, a liquid or other suitable medium. For example,it may advantageous for the environment to include elements that performa catalytic function to promote a chemical reaction in or between theconstituents in the mists. A characteristic enhancing treatment may beperformed on the formed layered organic light active materialparticulate. The treatment may be a temperature treatment, a chemicaltreatment, a light energy treatment to cause, for example, lightactivated cross-linking, or other characteristic enhancing treatment toimpart desired attributes to the formed particulate.

The constituents that attract and form the particulate may be given acharge to encourage the commingling into the particulate. For example,the first mist may be given a charge have a polarity and the second mistgiven a charge having an opposite polarity. The electrical attraction isthus enhanced between the first organic light active particulate and thesecond organic light active particulate.

FIG. 103 is a cross section of a coated cathode fiber having a blockinglayer formed on the cathode fiber and an electron transport layer formedon the blocking layer. FIG. 104 is a cross section of a coated anodefiber having a hole transport layer formed on the anode fiber and anemissive layer formed on the hole transport layer.

FIG. 105 illustrated the coated cathode fiber and the coated anode fibertwisted together to form an emissive fiber. In accordance with thisaspect of the invention, a conductive fiber is coated with the organiclight emitting material. A single conductive fiber can be coated withall or any number of the layers of the organic stack, including ablocking layer, electron transport layer, emissive layer, hole transportlayer, etc. A second conductor can then be formed over the organicstack, such as ITO, so that light generated in the organic stack isemitted through the transparent ITO layer. Alternatively, a conductivewire can be coiled around the organic stack to act as the secondconductor. As shown in FIGS. 35 and 36, as another alternative, thecathode and anode fibers can be coated with respective layers of theorganic stack and then, as shown in FIG. 105, twisted together to forman emissive fiber.

FIG. 106 shows a method for coating an electrode fiber with organiclight active device material. The electrode fiber can be spray coated,spin coated, dip coated and/or plated with the appropriate layers of theorganic stack. Alternatively, the electrode fiber can be vacuum coated,evaporation coated, etc.

These emissive fibers can be used for making items, such as lights,clothing, wall hanging and carpeting that emit light.

With respect to the above description, it is realized that the optimumdimensional relationships for parts of the invention, includingvariations in size, materials, shape, form, function, and manner ofoperation, assembly and use, are deemed readily apparent and obvious toone skilled in the art. All equivalent relationships to thoseillustrated in the drawings and described in the specification areintended to be encompassed by the present invention.

Therefore, the foregoing is considered as illustrative only of theprinciples of the invention. Further, since numerous modifications andchanges will readily occur to those skilled in the art, it is notdesired to limit the invention to the exact construction and operationshown and described. Accordingly, all suitable modifications andequivalents may be resorted to, falling within the scope of theinvention.

1. A voltage controlled light active device for emitting two or more colors of light, comprising: a first electrode; a second electrode disposed adjacent to the first electrode and defining a gap therebetween; a light active layer comprised of a mixture of a light active particulate and a conductive carrier material, said mixture being disposed within said gap, said light active particulate comprised of first emitting particles including a first electroluminescent conjugated polymer, the first emitting particles emitting a number of photons of a first color in response to a first turn-on voltage applied to the electrodes and emitting a different number of photons of the first color in response to other turn-on voltages, said light active particulate further comprised of second emitting particles, the second emitting particles emitting a number of photons of a second color in response to a second turn-on voltage and a different number of photons of the second color in response to other turn-on voltages.
 2. A light emitting device comprising: a first electrode; a second electrode disposed adjacent to said first electrode and defining a gap therebetween; a mixture comprising light active particulate dispersed within a conductive carrier material, said mixture being disposed within said gap and emitting light in response to an applied voltage, said light active particulate comprising a plurality of first particles having a first electroluminescent conjugated polymer emitting a first number of photons of a first color in response to a first turn-on voltage applied to said first and second electrodes and emitting a second number of photons of said first color in response to other turn-on voltages, and a plurality of second particles having a second electroluminescent conjugated polymer emitting a third number of photons of a second color in response to a second turn-on voltage applied to said first and second electrodes and fourth number of photons of the second color in response to said other turn-on voltages.
 3. The light emitting device of claim 2 wherein said conductive carrier is comprised of an electrically conductive material.
 4. The light emitting device of claim 2 wherein at least one of said plurality of first particles and said plurality of second particles includes members selected from the group consisting of polythiophenes, poly(paraphenylenes), and poly(paraphenylene vinylene), at least some of said members having substituents selected from the group consisting of alkyl, alkoxy, cycloalkyl, cycloalkoxy, flouroalkyl, alkylphenylene, and alkoxyphenylene vinylene. 